You are a "go to parent" because you are honest and approachable. Good job mom!
I think by guiding your children to have this girl tell her parents or speak with the counselor were excellent. But since this child is so frightened, yes , you need to speak with her.
As of Sept 1, here in Texas a child this young cannot be prosecuted for sexting.. They are just too young to realize the implications.
I agree the young man is a bully and a predator. She really needs to report him and admit she has in the past sent a sext but felt pressured and has regrets. What a terrible weight to have to carry around.
If you speak with her just listen to what she has to say. Then tell her she is not a bad person. She is just young and did not realize how it was going to make her feel so bad later.
Remind her EVERYBODY has made bad mistakes that almost the moment they do it, they have regrets. We are human and so it happens. The best way to get rid of this upset feeling is to tell her parents so they can help her. Let her know parents want their children to be safe and happy. They will want to help her.
Let her know that in the future, when she has that "strange feeling inside" telling her not to do something, that little voice and funny feeling is her own warning alarm. It is her heart and brain telling her to not do this. Not to take the chance and not to put herself in that situation.
It would be best if she could feel strong enough to go to her parents. If you feel comfortable, you may want to consider going with her. It can be as a "concerned parent with no judgement". I have actually been in this position a few times. The parents were just relieved to know what had been going on, they were not worried about me. I have never shared the conversations that we had in these situations. I made a promise and have kept it both times.
Or go with her to the school counselor and let the counselor contact the parents.
This child needs to unburden herself.. and this young man needs to spoken with and dealt with. He needs to leave her alone and know what he has done is also not a good choice. He needs to know people are aware of his behaviors.