I really liked how you depict this initial meeting between Maria and Natasha. The kind of mutual respect mixed in with distrust and curiosity works really well, and I think says a lot about these women. That they can see there is more to the other than what perhaps an initial impression (or previous reputation) tells them is a great way of establishing a common ground or similarity between them. I've not seen the movie or read the comic so I have no idea if this is how they meet in canon or not, but I think it's a great first meeting.

For some reason I looked at the characters but not the title, so when I scrolled back up to see if I'd been mistaken about a pairing list I noticed this was part one of six. (Clearly not the most observant reader. *g*) I like that this both stands on its own and works as a lead in to more interactions between Maria and Natasha.