Donation to Charity instead of accepting Gifts at Wedding - How do I word this?

by Amanda G.
(Maine)

Good Morning,
My fiancee and I are newly engaged and I'm so thrilled to have found my forever love. We're planning on having the ceremony and reception at our home so as to keep costs to a minimum but to also be able to accommodate all our friends and family.

Whereas most of our guests have children, including ourselves, we figured it would be the most relaxed and fun way to do it! I came up with the idea of, instead of our guests purchasing gifts or doing a money tree, we have all of our guests donate funds to a specific charity that I've long since contributed to.

My future husband and I are by no means well to do, but we do have just enough and try our best to remind ourselves to be thankful every day. In addition to that, I/we have an extremely healthy eight year old son who is our world.

We've come up with a creative way to "present" the donation idea to our guests, but my question is how to word it on our invitations.

I'd hate to sound crass or tacky (not that giving to a reputable childrens charity is tacky by any means) but I want to be sure to get the wording just right so as not to make our guests feel uncomfortable.

Any suggestions would be more than helpful! Many thanks and best wishes.

The Soon to Be,
Mrs. Libby