My sister wrote on her DD's invite 'parents and siblings welcome, however please let me know for catering purposes'.

I've always stayed at parties DD has been invited too. Most of the time she is clingy, or if it is a parent we don't know I'm not really comfortable leaving them there. And you never know what the place is going to be like until you get there - we went to one on the weekend where the house backed onto a creek, there was a jumping castle, trampoline (no net) and an elevated cubby house. Parents seemed nice, but I just had visions of children bouncing off the trampoline into the creek....... There were about 20 kids there I think.

Good games - musical statues, egg and spoon (use a golf ball), pin the tail on the donkey (or tiara on the princess etc). I've also found that they just like playing - if they're inside you'll find a few disappear into the bedroom or toy area, if they're outside they will use whatever you've got out there.

With numbers, when I was growing up, we were allowed to invite the number we were turning - so 6 people in your instance.