hi
im in agreeance with Bron ... its a 1st birthday not a 10th... this may sound harsh but forget the other children and focus on your little girl.. I have children ranging from 17 14 9 and 13months and on his b/day the older kids(who came and were family) did there thing and the younger ones played with Ali and each other.... Also if there family i would be telling them for them to organise their own kids ...or if they are interesting in a jumping castle ask for some money towards it..... REMEMBER a 12 month old still needs sleeps so dont be disappointed if she crashes from excitement half way through the day !