My head hurts 
I have found and booked a wonderful local venue for DD's 7th birthday party. For £5.95 a head, the children get 2 hours to explore the interactive gallery (soft play, parachutes, lots of things to do with light, sound and colour), watch a 3D film that takes them "into" the future, play party games with the party leader and each get a healthy packed lunch that is provided by the venue. They have also offered to make up a big personalised birthday banner for her free of charge
All I have to do is provide the cake. I am absolutely over the moon to have discovered this little gem, which just so happens to be situated in a beautiful world heritage site.
The problem is DD is in a composite class of 25 children - a mix of Primary 2's (18) and 3's (7), and I am a single, low income parent. 10 children would be affordable for me (perhaps a couple more at a big push). The venue is a minimum of 8 and a maximum of 20, so it already stands that we cannot invite everyone.
DD is best friends with possibly the two sweetest children in the world (twins - 1 boy, 1 girl), so a girls only party is out of the question as neither she nor I would ever dream of only inviting the little girl. This of course means we need to invite at least one other little boy so her BF isn't the only one. But how the hell do we decide who to invite and who to not invite?! I don't want to cause any upset, but my hands are tied by both available funds and the venue's restrictions. Also, two of the girls in DD's class are quite nasty wee things and frequently upset/bully her, and I'm really worried that them not receiving an invite will open the floodgates to more teasing 
Has anybody got any experience of dealing with this kind of thing and what did you end up doing? Am I being really mean and completely unreasonable to not just book the generic soft play party and invite everyone?