I came from an extremely strict, religious, straight laced family. Birth control was 'you just don't', period. Not good advice, however, when my husband and I decided to get married, we purchased (rather borrowed lots of money from the bank) to get a home 1 1/2 years prior marriage. We were financially strapped. We moved in together before marriage.
My mother, who was always prim and proper and was part of the 'holy rollers', turned to me one day and said, "I never thought I would say this, but, I'm glad you live with J. At least I know someone is looking after you and you're safe, you're not living alone." I was floored, that was the last thing I expected to hear from her. I was astounded that my Dad didn't call me every name in the book and drag me 'home' by my hair and tie me to the nearest tree. Point is, my worst fear of their reactions never happened. My Dad's family....with nuns and priests in the family, were equally accepting and now think that hubby is better than sliced bread.
Long story, the short, you'd be really surprised by the reactions of the people who truly love you. Sure they'll be po'd, but acceptance and support will follow after the 'shock' (it's more their dissapointment of their expectations). Your ages matter because the important lesson is not to hide your 'mistakes' but to be mature enough to accept the consequesnces of them. This is serious, get her some counsel, no matter what her decision. (Unfortunately, there's no easy out. She really does need support now, she sounds so scared.)