The short - and horrible - answer is that she won't live long enough to affect this part of his life. But he doesn't have to give her that answer, thank god.

"Me being here at all is likely affecting the future already," he says with a grimace. "As far as I know, Piotr never worked with a mutie in his guerrilla army. That alone would be enough to irrevocably change the history I personally know." For better or for worse - either making a good enough impression that Piotr doesn't hate him decades later, or making the man more determined to kill him outright. So he just throws up his hands a little. "Either we're in a parallel timeline or I'm already fucked."