My brother fucked up by not putting her on the pill when he had the chance. For the record she didn't live with him but that's no excuse. I gave her mother hell too.
I blame my brother for the "head in the sand" routine, and her mother for being an idiot. Her mother KNEW she was very sexually active (there's a backstory there too long to post here) yet did nothing to protect her or at least advise her accordingly.
Any parent whose daughter is over the age of 13 and isn't on the pill ought to have their ass kicked and HARD. Teen pregnancy is at an astronomical rate and rising every month yet there are parents who just can't see the forest for the trees.
IMO no matter how much you talk to your kids, no matter how readily available condoms are, no matter how careful they are, they're going to fuck around and it is only a matter of time before, in the heat of the moment, the raincoat is left hanging on the hook.
Not saying I know anything about raising kids in the practical sense, but I do have a brain (and use it sometimes). A perfect example is with a buddy of mine. He has 2 daughters, 13 and 15 (at the time). I said "have you spoken to them about birth control"? The 15 yr old yes, the 13 no because he said "she isn't into boys". I said "yeah, ok RIGHT, give your head a shake". No less than 3 weeks later she posts on her fb page that "she's in a relationship" and there's pics of her smooching a guy while sitting on his lap....I pointed this out to him and said "need I remind you of what my niece is going through"? Oh they're not like that. Oh REALLY? and not a year later there's a pic of them sitting around a campfire with 5 boys and they're all drinking beer etc. I said "you forget what YOU were like at 15 dude....."