That is a great gesture on your part. You have your heart in the right place. If you are looking other steem based charity's look up @sndbox https://steemit.com/incubator/@sndbox/exploring-sndcastle-communities-cultivating-steemit-growth-through-networks-hubs-and-projects This group is putting together projects around the globe. They have even met with the World Bank recently to receive funding.

Another noteworthy projects is running the World Community Grid on Boinc to wipe out diseases. They have several projects running currently to fight cancer, Ebola, Zika and more. It just requires running the boinc manager while you are on the computer. You can also get paid to help this cause through the grid-coin network. That way maybe you can generate more money to donate to your causes. Their is a whole group on steemit devoted this project.