akpayne, have you thought of giving the parents of the sibling family a letter stating that you have done some thinking and realized now that you have learned more about running your daycare that you must raise their rates? You don't have to raise them as much as the full fees (unfortunately) but you could think about raising them $5 or $10 a day, depending on what you decide to bring them more in range with your rates. We would be happy to help you with wording for a letter if you need us.