My friends parents let my friend have his friend stay at their house. his friend is a girl?

they are both about 14 sooo yeahhhh she is supposed to sleep in the living room and him in his room and she is from california and we are in idaho. so her parents let her stay at my friends house for a few days sooo yeah they arent like cousins or anything... "just friends" do any of you guys think something like mmmm, idk may happen there while she is there? (my friend is a pretty big man so dont think just because they are 14 they wont do it)