There's a lot to know about the Black Widow. Like how the reason she can't remember any time when this kind of shit didn't shape her life is because it started before she turned five, like how she learned violence, hunting and being hunted the way most kids learn body-language, eye-line, and what'll happen after they use which tone of voice with which adult.
That her first masters were willing to fight SHIELD outright and sacrifice other graduates from the same program for the chance at getting her back under control. That despite the fact that up to four girls every four years came out of the program, supposedly for interchangeable use, as far as the world's fucking concerned the title's now singular, and it's all hers.
That the last thing you ever, ever want to do is give her time to breathe or time to think or a chance to gather resources. And that until she's dead and you've killed her yourself and burned the body, she hasn't given up. She's just waiting for her opening.