Does this girl like me?

She is pretty carefree and cute, and both outgiong and shy. She knows me as an acquantaince, but I realized kind of stays away from me. I know I have not offended her and she is okay with me. Maybe I have shown I liked her, very subtly, but I don't think she knows. Does she like me? If she doesn't, tell me how I should ask her out. We are both on a swimming team, and only acquantainces, high-schoolers. What a re the words I should say to ask her out safely?