ALTERNATE VERSIONS
In Earth X, the Absorbing Man absorbed the machine super-intelligence of Ultron and was responsible for killing many of the oldest Avengers. Creel was only beaten when the Vision infected him with a computer virus, reverting him to stone and breaking his body into pieces. It was decided that a loose association of trusted figures would hide Creel’s pieces to prevent him from ever being reformed again. Black Widow was among those who took part in the pact. However, a doomsday cult known as the Tong of Creel formed and dedicated themselves to reassembling the Absorbing Man. Several heroes who possessed pieces were killed by the Tong as Creel was slowly reconstructed. Black Widow appeared among the Realm of the Dead as Creel approached full re-assembly, indicating either the Tong or some other force got to her behind the scenes.
The Ultimate Black Widow was very similar to Earth-616, on the surface. Natasha Romanov was a former KGB agent and super-spy who went freelance and defected to America after stealing intelligence from the Latverian embassy to sweeten the deal. She was partnered with Hawkeye 
and initially worked for the Ultimates black ops unit with him alongside former mutant terrorists Quicksilver and Scarlet Witch before they graduated to the public team. She was openly flirtatious with the womanizing Tony Stark and they began seeing each other. He later designed a combat armor for her and proposed by paying three million people from her home city in Russia to spell out “WILL YOU MARRY ME?” as they flew overhead. Naturally, she accepted.
This Natasha had a vicious streak that wasn’t present in her counterpart, though. She openly mocked Thor as a crazy man before his status as a true Asgardian was revealed. When he went rogue, she fought him in her StarkTech armor before faking a pregnancy and claiming his blows caused her to miscarry, stunning him long enough for a cheap shot. In time, it was revealed that Black Widow was part of an international conspiracy to destroy the Ultimates. Fear of America using their superhumans abroad brought together many opponents from Russia, China, Syria, North Korea and the Middle East. These Liberators crafted a plan with Loki, God of Mischief, to systematically discredit and bring down the Ultimates. After Thor and Hulk were out of the way, Captain America was framed for the security breach Natasha was responsible for. Black Widow then personally led the strike team that murdered Hawkeye’s wife and three kids before taking him prisoner.
The Black Widow thought she had Iron Man under control as well. She executed Jarvis and held Tony at gunpoint to keep him away from the destruction of the Triskelion and coup against America. She bragged about destroying the United States as they had destroyed her own country and promised Stark would only live long enough to transfer his fortune to her. Unfortunately for her, Tony Stark was a deeply paranoid man. The nanites which allowed her to pilot her armor 
were linked to his, allowing him to override control of her body and download secrets from her brain. Stark knocked her unconscious and suited up, with Iron Man joining the other Ultimates as they rallied and defeated their attackers. Natasha initially escaped by cutting her own wrists to bleed out the nanites and hiding among the many injured in the Liberators’ assault. Hawkeye tracked her down, however, and put an arrow in the traitor’s head for everything she had done.
In the Mutant X timeline, Black Widow was chairwoman of the Avengers, including Hawkeye, Deathlok, Typhoid Mary and Iron Giant Man. Elements of Natasha’s costume resembled Spider-Man’s, suggesting a closer tie to the web-slinger in this reality. In this world, Canada was an imperialist conquering nation, having subdued Russia, China and much of Southeast Asia. The American / Canadian border was therefore the longest and most heavily defended on Earth. Black Widow and the Avengers intervened when mutant heroes the Six attempted to cross the border
and rescue their missing leader, Havok. Natasha’s team was hostile towards the Six’s newest member, the second Captain America who was both a mutant and a former Avenger. He was considered a coward and a traitor by the team for an unknown incident, and even his former lover Natasha despised him. The situation spiraled out of control when Cap’s suppressed mutant powers surfaced. These powers and secret conditioning drove him mad and lead him to murder the Avengers before turning on the Six as well.
In the House of M, Magneto consolidated power on behalf of mutantkind, ushering in a very different timeline. The Soviet Union provided support to Genosha and their apartheid of Mutates in order to share the power over these weaponized mutants. Black Widow and the Soviet Super-Soldiers defended Genosha when it came under attack by Magneto’s Brotherhood. It was Natasha who recognized Magneto’s brazen assault was a feint and sent Crimson Dynamo to intercept Charles Xavier and Magneto’s children as they freed the Mutates to join their forces. The Dynamo’s assault crippled Xavier, and emboldened Magneto to end the fighting and claim Genosha as a mutant nation.
In Age of Ultron, Natasha was in San Francisco visiting her friends Richard Fenster and George Smith, Stunt-Master. The Ultron Singularity began as multiple cities were destroyed around the globe. Even George’s prosthetic arm was taken over by Ultron code, forcing Natasha to murder her friend after he scarred her face. She hunkered down at a S.H.I.E.L.D. safehouse with a 
passing Moon Knight, seeking a way to fight back. Natasha read Nick Fury’s hidden doomsday scenario plans and traced them to a special bunker in the Savage Land. She found Fury and many other surviving heroes, who had discovered Ultron was attacking them from a beachhead in the near future. The heroes attempted to storm his position using Doctor Doom’s time machine but, in the end, they were all cut down and killed by Ultron’s technological superiority.
In a future averted by the Inhuman Ulysses’ visions, Thanos came to Earth and wiped-out half of the world’s heroes on what became known as "Zero Day". Those who survived were reorganized by Madame Natasha into the A.V.E.N.G.E.R.S. Initiative and Thanos was finally defeated. Decades later, Natasha remains an active figure overseeing the Avengers’ roster of second generation heroes and legacy crime-fighters. Danielle Cage-Jones, that timeline’s Captain America, has interacted with the present several times, but Madame Natasha herself hasn’t visited her past.
What If..? (1st series) #38 jumped ahead thirty years to the far-flung future of 2013. Countess Natasha Romanoff returned home to lead a Russian revolution, ending Soviet rule of her homeland. She became President of the New Russian Republic and eventually visited the United States to meet with Vice President Franklin Nelson and his domestic affair advisor, Matt Murdock. Black Widow and Daredevil reconnected to fight the new Kingpin of international terrorism.
In an alternate take on Civil War, Contest of Champions #9-10 showcased a timeline where President Tony Stark led the mighty Avengers as Iron Patriot, while Steve Rogers and his conscientious objectors to the Registration Act were forced to carry out suicide missions as the incarcerated Thunderbolts. Natasha was a member of these Avengers, wearing the StarkTech Spider-Man costume fitted for her as the Iron Spider. They were dragged to Battleworld by the Maestro for his skirmishes to hold control of the Iso-Sphere. It was later uncovered that Stark used the Reality Stone from his time with the Illuminati to orchestrate his victories over the Registration Act. Natasha was among the Civil Warriors who stayed behind on Battleworld to fight a more honest war.
In the new Heroes Reborn, Black Widow and Hawkeye were a mercenary couple working for Baron Zemo and his Siege Society against the Squadron Supreme of America. The Siege Society served Zemo’s Hydra, a collection of Europe’s oldest, richest and smartest minds gathered in defense against the imperial aggression of the United States. After the Civil War which made a rift between Hyperion and Nighthawk, the Siege Society infiltrated the Secret Squadron’s headquarters in London.
On Battleworld, several iterations of Black Widow were known to exist. In Arcadia, Natasha was one of many members of A-Force defending their domain. Black Widow was also a member of the Avengers of the Holy Wood, protectors of Baron Simon Williams with a friendly rivalry towards their neighboring Guardians. In Killville, Black Widow was part of the Assassins Guild who failed to kill M.O.D.O.K. and Angela. A near-perfect recreation of Black Widow lived in the Kingdom of Manhattan, a domain which artificially preserved the heroes of Earth-616 and Earth-1610.
In several realities, the Black Widow was survived by her children. Avengers Next starred James Rogers, the son of Steve Rogers and Natasha Romanov. In Captain Marvel: The End, Natasha and Clint Barton survived the Second Last War and had a daughter, Katie Barton, who outlived them by 2051. In Daredevil: End of Days, Natasha had a daughter named Mapone Romanov with Matt Murdock before they both died. Blind from birth and calling herself Stick, Mapone became sensei to Tim Urich, the next Daredevil.