Instead of giving money, especially a large lump sum, which it would be hard for them not to feel weird about, I would think, why not just fund the needs that you see? Buy the guy new rain gear, pay some or all of the cat's vet bill, etc. Tell them you admire their values and want to help them be able to live them, as they are currently doing. You can also take pressure off by inviting them to dinner, showing up with a bag of groceries, etc. Smaller, more frequent gifts such as these may be more easily accepted than grand gestures.