Supporting older/elderly parents or minors is not the same as supporting two able-bodied adults in their prime earning years. The fact that bil wants money to keep his barely surviving business afloat is an even bigger problem. Bil's business can very quickly become a financial sinkhole.

My father educated his younger brother and supported him until he started to earn. Then he educated his nephews who were the sons of his eldest brother. All of them are doing very well now. My father considered it his duty and never asked for anything back in return. There was never any question of anyone repaying him back all the money that he spent. It was obviously a financial burden on my dad but to help out the family is the best thing he could do as it made all of them affluent and successful.

My parents were poor Asian immigrants. I started working as soon as I was able to. When I got my first real job, I used to send my parents around $500 per month. Then it became $1000. Now we support them 100%. We took over the mortgage, pay all bills directly and I give them $1000 per month for spending money. It's probably around $5000-6000 per month now.