In your case, I understand and you shouldn't feel too bad about it.
On the other hand, the more sensitive kids like the girl who cried must have been felt left out and wondering why she wasn't invited.
I was often left out and never invited to parties as a child and it still sticks with me today but it was my fault as I was too scared to form bonds with kids my age.
Maybe next time you should have a party with only the real/closest friends of your daughter ?