K.,
Oh you're poor little girl :( It certainly can be hurtful to be the one singled out, and LEFT out of the fun. I hate to think that the mother would allow such an inconsiderate thing to happen to a 3 year old girl. So, I am inclined to believe that 'something' happened and it was not intentional... whether she simply didnt' get an accurate count of the kids, or the invite was somehow lost, or whatever, but I cannot imagine it was intentional. (at least I hope not).
If i were in your shoes, I would mention to her daycare person something like 'Is there a birthday party coming up that the kids have been talking about? can you explain to me if there is something happening with my daughter to cause her to be excluded from this event? she's been hearing the other kids talking about it, and I have to say that her feelings are very hurt that she wasn't included and I wanted to ask before I lost my composure with the other mother for being so inconsiderate of other kids feelings...i'd like to give her the benefit of doubt but at this point I am a little focused on helping my daughter deal with the rejection. Is there anything you can share with me about the daily interactions so I can understand better, or did she simply get overlooked?'
I would be slightly confrontational but not overly so...
I would definitely speak up though... and not in front of your daughter if possible. Then you have to think about what you will do if you get the late invite... because then at that point it's almost like you asked to be invited,...
I would probably send a card to the child with a 10$ gift certificate and gracefully decline attending but saying thank you for including "sally" (or whatever your daughters name is). But that's because I tend to be passive-agressive sometimes and cannot always control my censor button in social situations :) you may have complete control of your mouth, but i'm still mastering mine :)
LOL!
Good luck to you,...