Frustrated with another Mom of a kid in my daughter's Daycare

Malorie
I'm throwing a small birthday party for my 4 yo daughter. From a small house. Where both sides of our very large families are planning on attending. So, I told my daughter she could invite 3 of her friends from daycare.
Yesterday I got an email from the Mom of a kid in the class who was not invited. She wanted to know why she didn't receive an invitation. I explained why, but told her her kid was welcome to attend.
She replied back and declined the invitation. Why, in the name of all things holy, would you ask why your kid wasn't invited if you have no intentions of attending? Why!?
*grumble*