I would like to donate what I can money wise while my grandson and his parents are staying there. How do I make this happen?

Just call them and donate.

I also like to tell everyone i know about the amazing things they are doing. Then politely ask they throw some money in the box at McDonald's each time they are there (or just stop by and throw a few bucks in). You can also send a check or drop it by. I drop by because it's heartwarming to see how wonderful they are to everyone

While i was staying there my aunt made a donation. She mailed a check.

They typically don't request a monetary donation until someone checks out. When your grandson's parents check out, you could call them and make a donation, or they could tell Ronald McDonald House that you will be making the donation in their behalf. I'm sure that you could call and make a donation at any time.