L.H.
More than likely it was completely innocent. They’re 6 so very inquisitive and impulsive.
I think the main thing to do is ask her questions to try to get more of an idea of what happened but not let on that you’re alarmed. Maybe “daddy told me something happened today with a boy and your shirt, can you help me understand what happened?” Listen and ask any questions as calmly as possible.
Then I would work with her on what to do when someone makes us uncomfortable. He stopped when she told him to. Good for both of them! She was assertive when she told him to stop. She may have been embarrassed (my daughter tends to get really angry/upset when embarrassed too) and tears are probably due to that.
I would praise her for telling him to stop. Empowering her to find her voice/courage to stand up to ANYONE who is making her uncomfortable or doing anything to her body without permission is important for sure.
After listening to her, I would then decide whether it’s important to talk to her teacher. I’m inclined to think that this will be an isolated incident. I might mention to the teacher “Clara came home quite upset telling me that George lifted her shirt. She told him to stop and he did, so I’m confident it won’t happen again. I just wanted to make you aware.” Then she knows to maybe keep a closer eye on interactions and remind all of the students to keep their hands to themselves.
The thing I hate about the times we live in is seemingly innocent things done by children get blown way out of proportion (like the kid that gets suspended for kissing a girl on the cheek in first grade).
There has to be some kind of common sense applied.
Good luck and I’m sorry this happened to your daughter.