You don't say how old she is, OP, as that would make some difference to what you say.
I have an almost 17 yr DD with 16 yr old bf of nearly 10 months now. We have had a few chats about some aspects of physical relationships in which I have pointed out to her that many teenagers "knowledge" of sex comes from unrealistic porn etc and is not based on real relationships.
I have told her to ignore peer pressure ( she has one friend who is repeatedly telling her that there must be something wrong with her bf because they have been together for 10 months and not had sex yet and that it is not a "real" relationship!), and that the only right time to have sex is when they are both ready and feel it is the right step forward for both of them. BF seems to be in no hurry and is apparently happy with the way things are- in practical terms since they are both boarders, even though they have some opportunity for privacy at his and her homes, they have had no real opportunity anyway.
I encouraged by DD to think ahead about contraception and she went to GP and got the pill- sadly really didn't agree with her after 2 months it had a terrible hormonal effect on her so she stopped taking it- so she could try it for a while without worrying about whether it was working or not. So she is having a break and will try another brand or patch next month.
My key messages have been that a) communication with bf is the key- if you don't want to do something/ it doesn't feel right then you explain that and why. If someone really loves/cares about you, they will understand and it is your body and only you can decide how anyone else touches it etc.
b) Don't listen to the "playground" bragging- most of it will be fiction.
c) whatever happens- if anything goes wrong ( ie possible contraceptive failure, soreness of whatever) she/they can come to me and I will not judge- just help them sort it out.
If you are already talking a bit about it, sounds like you are doing a great job anyway!