Keyloggers can help you know what your kid is doing behind your back when you are not around... : https://www.geckoandfly.com/17868/best-free-keylogger-for-windows-mac-android-ios-to-monitor-your-kids-facebook/
This one seems easy to use... : https://kidlogger.net/
I know there are many mothers on Ovarit who may find this useful!
That might well be such a last resort situation. How deeply they've also damaged their daughter's trust in them is what they will have to deal with too.
You're welcome to leave it at that, I said what I said and fortunately for the abusers and psychotic control freaks on the internet I can't physically stop all of them from creepily spying on their daughters. I will certainly continue to stop all the abusers I can and do what I can to advocate against their creepy behavior though. You have a good day as well.
Respectfully, I have seen computer monitoring software be used to prevent a girl from being groomed by a much older parent (edit: man, not parent) The non custodial parent was only able to get the custodial parent on board with reduced internet access and therapy once she was able to prove to him the child was being groomed.
I trust that you and I can have different opinions on this and leave it at that. My reasoning is just as acceptable as yours. Have a good day.