Inappropriate language and speaking to random people from games

[Upsidedownrightnow]

My dd is just about to turn 13, I checked her phone and she gave a random person from a game her number, she even talked about it when her so called 'boyfriend' and said the random person is probably a pedo so she knows what she is doing is wrong. We have spoke many times about not talking to strangers.

So has been friends with a boy from school for some time and recently started calling him her boyfriend in texts to him and he calls her his girlfriend.

I checked her messages and last night he was speaking quite crudely and she was just like yes please.

I'm not sure what to do?

She knows it is dangerous to speak to strangers so she intentionally broke that rule which we both agreed.

Also the talks between her and her boyfriend are not appropriate for her age I feel and I'm not sure what to do about that.

Any advice is welcome as I really don't know what to do.

My current feeling is to take away the phone and ipad as we had both agreed before she would not be in contact with strangers.

I don't know how to approach the sexual type of talk between her and this boy.

Also I want to add that i also feel bad for taking away her phone and ipad right now as she has no other way to connect with friends during lockdown but she knows what she is doing is wrong

It happens and it seems inevitable. They should have a bigger maturity of older people to avoid that.
You did the right thing to check her phone and since she broke the rule you need to check it often in the future. Put a good parental control on her devices and block inappropriate apps, websites and limit the screen time. Apple devices have a buit-in parental control, Family Sharing, you just need to activate it, for android devices there's Family Link, both totally free.
Even though these don't allow you to read messages they will be a good help to avoid insane situation like that, in addition to avoid phone addiction, bad influences and all the consequent stuff (lack of sleep, depression, bullying,...). I read about Bark parental control that alerts you of potentially inappropriate messages, letting you to read them, but it's not free and honestly this bothers me, you can read her messages when she sleeps if necessary, because she shouldn't use it at night. Recommended screen limit for teens is maximum 2 hours a day on any screen, one hour on phone could be still good, no at all during the night starting one hour before bedtime (which I suspect is the time when most of inappropriate stuff happens).

I wouldn't take away the devices but for sure I would put the parental control, block that game (and maybe any app) with the chat, inappropriate socials, turn on the feature that allows to install new apps only after parent's approval, and limit the screen time, maybe to maximum one hour a day or even less until she shows she can be trusted completely.

This will still give her the possibility to connect with friends but it will also avoid useless, inappropriate or dangerous stuff, avoid screen addiction (getting better sleep), allowing you to have a better control of her online activities, now and in the future.
Then I would talk about boyfriend, sex, relationship, self-esteem... more broadly speaking, not necessarily about the messages you've read. I would explain you cannot actually know a person just looking at his/her online messages and posts, it will be totally a mental thing... like dreaming, real life is different and truthfully much better, real feelings are not comparable to the "online" ones.
Last issue about the potential dangers online, the reasons for which her behavior was wrong... you've already done and she knows that, anyway a refresh could be useful. The problem is teenagers follow just their impulses more than their right thoughts, they agree with you and later they do the opposite.