That's about it really. DD has a friend at school, they have had the occasional play date (hate that expression, but can't think of another!) I invited her to DD's birthday party, but she hasn't reciprocated.
It was a sleep over, that's all, but my DD has never been to one. I suppose the fact that she is not dry at night would have been difficult, but her friend and her Mum don't know this anyway, so can't be the reason that she wasn't invited with some of the other girls from the class...
DD heard about it and wants to know what a sleep over is 
DD even knew it was her friends birthday, which is a great achievement (she has ASD and MLD and doesn't usually take note of such things.)
And I just feel sad and angry - I have had a couple of coffees with her friend's Mum, she seems nice but she likes to quiz me about my DD's special needs, as her daughter is on the school's SEN register too, and she thinks that it is the worst thing in the world for her daughter to be on school action. 
Hey ho, just goes with the territory I guess...don't suppose that I will bother to mention it next time I see her Mum; then again I may just ask what she did for her daughter's birthday just to watch her squirm...but that would be a bit passive aggressive...need to work on being assertive instead!