i'd also tell her that if someone reports her boyfriend he could get done for statuatory rape
now, this is rarely actioned by the police to court as far as i am aware - but it served as one of many ways i discouraged my kids - particularly my boys aged 16 having sex with 15 yo girlfriends
I also drove them personally to family planning
got them to see the nurse at the doctors - cracking woman had them in fits of laughter - using a banana and a condom
took dd to get the implant ( thats a whole other story)
kids can be stupid - i mean incredibly stupid - it wont happen to them, they wont get diseases, they will love each other forever, a baby wont mean too much disruption they will get benefits and they can pay for everything on £40 a week 
I mean so stupid its scarey.
so i would tell her mum, then tell her mum you will take her to doctors, nurse, family planning, get the implant, get a shitload of free condoms etc
when i took my youngest son and gf to family planning - i waited in the car, they talked to the gf alone and in confidence made sure there was no pressure involved etc,
i mean there was some really good advice out there - however they were mortified as i marched them to the car
i mean i marched them!
can you imagine your mum taking you to a family planning clinic?
I would seriously havre died
but these things need to be done