My 7 year old daughter went to her first sleep over on sat. The family took her and 2 others (including their child) into town to buy the birthday girl's birthday cake. Whilst they were in the shop, one girl stole a packet of sweets which I think they all knew about. My daughter says she told child not to but was told that they would be told off hence no adult was told. The girls then went home and sneaked off to eat the sweets, until the Dad realised something suspicious was up and found out what was happening. I wasn't aware until we picked our daughter up yesterday morning. Feeling upset that she was involved but didn't say anything to the parents. She didn't seem particularly upset until I told her she should write a letter to the parents apologising - I don't see it as their fault as they couldn't keep their eyes on the children all the time. Am I over-reacting?