Gyokuko, thank you for asking! I believe that your request is more than appropriate for posting here. I quote, below, the Forum Rule that I think might pertain:
4. The forums are free of charge. It's all right to mention your own publications or the type of work you do, but please do not post for the purpose of advertising your own or someone else's commercial business. Links to personal blogs are acceptable so long as the linked material doesn't violate any rules here, especially #18 below.
Gyokuko, your purpose is clearly not "commercial".
Which is to say--that you are not seeking to sell services for profit. You are simply requesting donations for a project designed to benefit many, beyond Dharma Rain itself as an organization.
I say go for it!
Lise, Mark, and Isan may, of course, have different viewpoints. And yet, I suspect that we may well be in agreement here.
My colleagues may have alternative or additional suggestions on where you might post. Off hand, I would suggest posting on the "Keeping in Touch" forum--or the "Here and Now" forum.