Like the others have said I would talk to the carers but keep in mind that it might have been a bit made up. You mention she hasn't learnt about fibbing and getting out of trouble etc. but I have mummy friends who's kids tell them they eat pizza everyday at CC and don't have naps, when infact the carers notes and circulated menu tells mum that they did not have pizza and they did have a sleep. Being a bit generous with the truth can happen even when there is no real purpose IYKWIM? But talk to the carers, they would know if the children where even in a position for this to have happened.