Hi,
Ultimately this is your friends decision, but there are a few things you can do to show her that she would have support through an unwanted pregnancy.
Look in your phonebook under "crisis pregnancy centers" or you could also call the numbers that are listed on this website. See what kind of local support there would be for her (ie, a place for her to stay if she cannot live with her parents, help applying for state aid/food stamps and medical, help with baby supplies/clothing.) She’s probably terrified.
If you start making some calls on her behalf, she will see that she can count on you as a supportive person and this might impact her final decision.
Good luck.
Vanessa