Am I overreacting or was I in the wrong?

My friend and I have known each other for a decade and our families are all very close. Our children go to the same schools and are all best friends, we do lots as families like dinners, holidays ect.
My middle child was being nasty online to some other children and my friend’s child was also involved in the master being nasty. I found out as my youngest told me a few days later as it was playing on her mind ( she didn’t know the extent of it but didn’t want to keep it from me)

When I confronted my child she was very angry I found out and doesn’t have much remorse ( she has been dealt with) however I told my friend about what I had learnt with some evidence and explained that both our children were involved.
I didn’t blame her child I just wanted her to know incase things escalated and if something happened to her child (there were threats of bashing between other kids) I wouldn’t forgive myself if they got hurt and she didn’t know what was going on. If my child has done something wrong I would like to know.

I feel like my friend go the impression that I was attacking her child but that wasn’t the case.
She is my best friend and I don’t want our friendship to be ruined.