to have an age appropriate sex talk with dd who is almost 7?

[ItsAllAboutTheCakes]

Dd has a very good understanding for her age but one thing we've really struggled with us the subject of masturbation in public, I know that's not what she sees it as because if her age but just using correct terms rather than faffing round sugar coating it (dd calls it rubbing)

I've had various teachers approach me as she rubs on chairs at school, I've had various conversations about how it's fine and natural for that to feel nice but she needs to do it in a private place and not at school. We have been to the doctors to rule out thrush, worms or any underlying issues and she us just rubbing because it feels nice.

I've tried to explain again to her today that while its fine for it to feel nice it's not ok in public and as she doesn't know why it feels nice she doesn't understand why she can't do it at school sighs.

its been a long road and I'm at a loss as what to do next. She will be 7 soon and goes to juniors next year.

I've tried being more firm, I've tried having long drawn out discussions.
Any ideas what I could say or do to help explain everything? She already knows about period and where babies grow, where they come out of etc.

I feel your pain op my DD used to do this as well, started about 2/3 she'd rub off the carpet or arms of sofa through her nappy. It seemed to taper off until she started school then it started up again (I didn't know she was doing it at school). I used to just remind her at home to not do it in front of people and that its for private. Then one day her teacher called me in and said she had been doing it at school but it wasn't as if she realised she was doing it she just seemed to be doing it when the teacher was talking or when she was concentrating. She asked if I would take her to the doctor just to rule anything out and if she was still doing it they would provide her with a squeeze toy to try and encourage her to use that. They were really great.

There was no infection so I just had a chat with her again about it being for doing in private and it has stopped again (she is 7) no idea if she is still doing it here or not so something must have sunk in