It isn’t guaranteed that she will get pregnant from IVF but unfortunately it is expensive. However, if she does have a baby, make sure it is your father’s because it could be the pool boy’s. Your father won’t get a paternity test and would be angry if you asked, but you can test the baby against your DNA and get a sibling DNA match. However, unless he catches her cheating or she does something horrible, she is here to stay. Proving the baby isn’t his would do it, but don’t count on it. Sadly, your father is a lost cause.