It's not likely she'll get preggo, but if she does, life as you know it will change. Get her to take the pill.
I have a buddy with a 4 year old little boy who swears she was on birth control AND he pulled out. Life is good for him now, but he was ten years older than you when it happened, and it still sucked for him.
I do not play the odds on things like this and I recommend you error on the safe side.
Female liar in bold, a single skipped pill doesn't cause shit, she trapped him