Dd's party yesterday. I sent out invitations a while ago including one to a girl who's mum I don't know very well-only to say hi to at school gate.
This mum replied to the invitation by text saying that her daughter would love to come.
Stupidly, I didn't reply to the message.
Said girl didn't turn up yesterday which was a shame as there were only a few invited so it stood out. The other girls asked where she was and dd said she must have got lost on the way 
I know I probably should have replied to her message with a 'great, see you then' but the message must have come through when I was distracted.
Awkwardly we have another party to go to today-what do I say if this mum and girl are there?