New at this!

[Crayola kiddies]

I would suggest you draw yourself up a contract cause it protects you as well as the parents as it clearly sets out what is expected by both parties. I don't give a sibling discount cause a spot is a spot and it doesn't cost less to look after two children just because they are related. Hopefully this family is not your friend, neighbour, or family cause that definitely makes it harder. At pick up I would have a chat with the parent saying that there have been some issues with the boys and that unfortunately you will no longer be able to provide care. Now without a contract you are not obligated to give them any notice but to avoid giving yourself a bad name in case she decides to spread the word you should give her some time to find new care ... Such as two weeks. Hopefully you get paid in advance and if you do make sure you tell her after you get the next two weeks payment. If you don't be prepared to get stiffed. Good luck