Does the school want you to send $ directly to the school? To the PTA? Or is it one of those outside companies that takes a cut of the donations?
Charity donations are a personal choice. Just pitch the flyer and don't worry about it.

Got those donation request form from school again. The kids keep asking me to give more money so they can win T-shirts. I have my charity deduction from pay check to get the company match, and I really can't ask family and friends to contribute so it's out of my pocket every time. If I don't contribute, will my kids be judged at school? Please tell me the truth. I feel bad not to give if being asked but am really short of cash.