Just returned from Playa Del Carmen (40 miles South of the Hotel Zone), and I hooked up with a great charity there. It's called "Charitable Tourism". They encourage tourists to bring an extra bag of donations for the kids. We took a carry-on full of paper tablets, lead pencils, color pencils, markers, crayons, toys, flip flops, etc.. Please consider doing this, contact them through their web site and they will arrange to meet you. You may get a chance to visit a family or two to see your donations disbursed. They focus on Cozumel and Playa Del Carmen, so this works well if you are on a cruise too. https://www.charitabletourism.com/