@connie26 At the very least get her on contraception, if she does have sex she needs condoms, he may not bring them. Tell her that him not wanting to use them cause of the 'feel' is stupid, make her remind him of the responsibility of fatherhood if he says no. Also, stealthing is a crime, it's legally SA at least but also rape - that's when you agree to wear a condom, then take it off without their permission and without telling them.
On BBC iplayer the show 'I May Destroy You' talks about it, I highly recommend watching it with her, just in general as I think it is very useful for women these days. Also might open up conversations.
Get her the morning after pill now and give to to her, so that if it does unfortunately happen, the money or the shock isn't a barrier to her using it or buying it. Also something like the injection, implant, or the mirena or copper coil as its non-hormonal, as those don't reply on her taking it every day and forgetting. Also, reproductive coercion is a thing and he may coerce her into not taking it.
These are mitigation efforts to make sure the worst doesn't happen, maybe as she goes into Y13 especially closer to exams many people stop their jobs to focus on exams as it's very stressful. If she does, make sure she doesn't get a job back there.
Talk to her, have the conversations on stealthing and the coils, implants, injections etc, give her the morning after pill to keep, and condoms, and talk to her about reproductive coercion. Also get her to download the app called the E-Card, essentially it has an app so that at any pharmacy or sexual health clinic you can get free condoms and lube etc under 24. It also has a map for all the nearest sexual health clinics, also share a link to the website/app (I think they now have an app) called 'Brook' with her, I recommend it for all young people, it's free sexual health advice, contraception advice, love and relationships. All broken down and age appropriate. Just keep in conversation with her, make sure if signs do show you intervene. That goes for all relationships but be there for her from now. Just in case.
https://www.brook.org.uk/