YES. Excellent point. Both stories can be looked at from a broader perspective as being about the ways society and individuals try to groom girls and mould them into certain preset shapes of womanhood or personhood, and then the long-term damage those expectations cause.
I’m going to bring it back down to the micro level and focus in on that “not letting anyone in” aspect, because it’s so true, but they both seem to be at interestingly different levels of that in regards to how it fits into their found families, another theme which they both share.
For Trish, found family and letting people in pretty much sits at Jessica. She didn’t seem to have close or healthy relationships with anyone outside of that (and even that one has shades of dysfunction like jealousy and codependence, etc.). It goes deep with Jessica, and she had that support from her teenage years, and it saved her in many ways. Of course, it was also suddenly ripped away and is in the process of being repaired, but while there’s scars there, there isn’t any doubt it’s still them against the world. (We didn’t see what those days when Kilgrave controlled Jessica were like for Trish. How did he deteriorate their relationship? How maddening and heartbreaking was it for her to know something was off but not be able to do anything about it? And then when Jessica was free and in control but completely traumatized and made a choice to cut Trish out, and for her not to be able to help and protect Jessica in the same way Jessica helped and protected her.)
Meanwhile, for Natasha, even though most of her relationships aren’t very developed, there’s a lot of depth implied throughout several of them. Nick, Clint and his family, Steve. And she’s come to see the rest of the Avengers as her family, to the point she was less focused on what was right or wrong about the Accords and more interested in finding a way to hold everyone together during Civil War. But she still seems to keep a certain distance from even the people closest to her, and CW put an incredible strain on those relationships, and it’s not really clear what they will look like moving forward. (Oh, and hey, Natasha also knows what it’s like to have a brainwashed best friend that helped support and save her at the worst time in her life, and all the pain associated with it, albeit he was brainwashed for a shorter time and she was in a position to take action to help him.)
Anyway, I guess basically what the bigger point is, they both have a lot of surface relationships. They interact with tons of people in a professional setting and are very socially capable in those situations, but it generally doesn’t go deeper. They’re good at keeping people out of the deeper stuff, but they both have their own found families too, and they are very protective of them for obvious reasons. I think Natasha, despite being more of a lone wolf, has a bigger support system, at least in theory and even after the events of CW, but she’s not particularly comfortable connecting with them and sharing parts of herself and communicating what it means to her. Trish, more of a team player, only has one important person but is very open and frank about what she feels and what that relationship means to her. And that both fits with and contradicts how they tend to interact with the world in general or at least how the world perceives them.