Disclaimer: Everything you recognise here either came from the MCU films or the original Marvel comics, but I hope you enjoy the results anyway
Feedback: Feel free
AN: This scene takes place literally just after the events of Black Widow (with the obvious exception of the post-credits scene), looking at Yelena's activities after Natasha left to work on rescuing the Avengers from the Raft.
The Legacies' Triad
On other occasions, changes can be inspired by such simple decisions that nobody will ever realise the true significance of their choice, such as deciding to deal with a particular matter earlier rather than later…
Once she had parted company with the rest of the Widows, Yelena had set to work on choosing her target.
She recognised why Natasha had chosen to go back to the Avengers, of course, but it didn't stop the initial jealousy Yelena felt about the idea that Natasha was essentially choosing something else over her. On a pragmatic level, it made sense to ensure that the heroes were available to respond if something came up, and if her sister would break out the father they hadn't seen for at least a decade she could never abandon the people she'd actually been fighting alongside for the last few years, but still…
She pushed that thought down in frustration; brooding about the reasons why her sister had made her choice wasn't going to change the facts of the situation. The Widows who had been directly under Dreykov's influence had been released to live their own lives, and she had a full list of the others she could go after to free…
Alone.
She had spent years alone since she, Natasha and their parents were returned from that undercover mission in Ohio, but it was only after those last few days that she realised just how painful it was to be alone. Even without meeting them, she could understand why Natasha had fallen in so easily with the other Avengers; in a world of people who could never understand her own unique experiences, Natasha had found a new kind of family in the only other people who had any hope of relating to her… and Yelena couldn't afford to be a part of that right now.
If she was going to save her fellow Widows, she couldn't afford to stay in touch with her sister when Natasha was already being potentially tracked by General Ross. Government contacts might help them track the other widows, but Yelena couldn't afford to take the risk that someone else wouldn't just try and take over Dreykov's plans; she knew from grim experience that giving people access to that kind of power could trip up all but the best of men, and General Ross was far from that considering what he was likely to do once he had power over the remaining Avengers thanks to the Accords…
Yelena pushed such thoughts out of her mind; she had to focus on saving her sisters before she could worry about such wider issues. The list Natasha had downloaded from Dreykov's database had given them something to work with, but there was such a long list that picking her way through it completely on her own would take far too much time. She had sent a few of the other Widows after some of the more straightforward targets on the list, such as a few deep cover Widows who had apparently been 'programmed' to just monitor certain targets and report back to Dreykov at certain times, but there were a few on this list that were potentially trickier.
Yelena couldn't have known it, but as she scanned down the list of names on her electronic pad, in a world of limitless possibilities, her choice would have led her to a straightforward hunt for a relatively random Widow on a comparatively unremarkable assignment. In so many of these worlds, the lives of Peter Parker and Kate Bishop would have comparatively drifted apart over the next few months, as Peter's focus on his life as Spider-Man and Kate's own increased commitment to her training led to them spending less and less time together, until the two of them stopped even thinking about each other in depth by the time they both became part of a particularly unique world.
In this world, however, Yelena's finger rested on a name and tapped up an icon that revealed an address in New York and a list of rumoured activities and assignments for this particular Widow that immediately caught her interest.
Tracking someone in New York might be a risk considering the Accords were still in effect, but considering that nobody enforcing the Accords knew about her connection with her sister, it should be safe enough to at least do some reconnaissance and work out what this woman had been doing on Dreykov's behalf before she decided what she was going to do about the issue.
If nothing else, she might enjoy the opportunity to see more of America once the immediate threat had been dealt with; maybe she could even try and take a look in her sister's room in that old Tower before Tony Stark finished selling the building off…
AN 2: And that's that; this fic will be on 'hiatus' until I've finished a couple of other projects, but once I get back to it, we will start with a more familiar chain of events, as Peter Parker faces his first big solo threat… before things start to more obviously change from the events we're familiar with, anyway.