Advice please from wise MNetters. A bit of background first. DD is friends with twins. I'll call them A and B. DD has been friendly with the twins since starting in reception at school. In this school year (yr 5), DD has had problems with B's behaviour. No issues with A. The class teacher was informed and has been dealing with it. One of the main issues has been B lying about lots of things which has got DD into trouble, but B has also done this to other children too. But I've spoken to the teacher only about how this has impacted in DD and not mentioned the other children.
So, to the reason why I'm posting. DD is having a party for her birthday, and only wants to invite A. She will not budge on inviting B, and I feel it's my DD's right to invite who she wants. How do I, and DD approach the inevitable question as to why only A has been invited (before, both A and B have been invited to parties)? It's also possible that B may say she's lost the invite to her parents. I am friendly with A and B's mum, so want to pitch my response well.
Any suggestions please. DD is turning 10.