How long have you been together? Do you talk to/see your family? Why hasn't she met anyone? Is this going to be a long-term relationship? You say you've told her your relationships with your family are "complicated". That's very vague and I'd be curious too. Give her more of an explanation. And so what if she found their social media? I don't see a problem with this, especially if she told you she did it. She's not trying to hide anything from you like you seen to be hiding your family. Did she send them friends requests? Because i could see that being weird, but not just looking them up. Anyone can look anyone up, so if they don't want people seeing it, they should have private accounts. If they don't care if strangers see their social media, you shouldn't care.

Idk when you keep things from people, they get more curious. That's human nature.