DD(11) had arranged to go for tea at her friend's next week and comes home today saying she's not going because she's just been invited to a sleepover at another friend's house on the same evening and doesn't want to miss it. The first friend is not invited to the sleep over (the two girls don't get on particularly well).
I told her she should stand by her first invitation, cue tears and sobbing that all her other friends will be at sleep over. Apart from anything else, how on earth would I explain to her first friend's mum why we're cancelling? She's the only one the first friend's invited for tea.
AIBU? Any advice?