Did I do the right thing?

This is probably more of an AITA post, but maybe its a spot check too.​Happy hetero father of 4, oldest girl is 9-going-on-19. About 6 months ago, she tells me she thinks she's gay. I ask a couple of questions to make sure she understands what that means, she does-ish. She explains that social media she watches with other kids at her daycare helped her realize it. Ok, no prob, thanks for telling me, i love you...​Flash forward to now, she has a "girlfriend", and the girlfriend is having a sleepover for their birthday. So by my mind, I wouldnt let her stay over at a boys house on principle. Why would I let her stay at her "girlfirends" house?​I call GF's mom and delicately explain my concerns. GF mom is floored. She had no idea and doesnt believe it. Fine, not my problem. So i explain that perhaps she should talk to her daughter about it, and see what the reality is. Theyre 9-10, and its a weird modern world.​So I told my daughter about what I did, telling her all of the above, and explaining about what is and is not appropriate. She understood and was very upset. When I again stated that if this was not a romantic "girlfriend" , I would have no problem letting her sleep over, she started to waffle on her position.​I dont care if she's gay or not. I care that she is safe. I wanted GF's mom to know the clear stakes of a sleepover with my daughter. Honestly, if GF mom is cool and is going to watch closely, I'm probably 50/50 about letting her go. But because mom had no idea, and I've seen the digital evidence, I think it may be prudent to stick to my guns. At the end of the day, I cant help but think---- "She's 9. What does she know about love or sexuality?" I know thats flawed thinking, and I need to keep supporting her reality, while guiding her on the path to making good choices.​Did I do the right thing? via /r/Parenting http://bit.ly/2MB2RgA