I'm not selfish, but I'm not stupid either. If I gave cash, it'd be ...
I totally agree.
My wife has 12 siblings. One lives far away. 2 or 3 have, or have had, enough money to live middle class. You can't give cash to my mother-in-law, for she'll give it away to some of the other seven "children" (ages 34 to 55) "in need", and then be herself in real need.
So you pay part of the rent, part of her doctor's bills, part of a vacation. And help some of the others in a different way.
It was hard for my brother to understand that it was not "natural" that only I financed our mother when she was ill (hospital bills, stay-at-home nurse, etcetera). We had some very tough discussions ("Mexican bricklayers in the US pass hunger and cold just to send their mothers a few hundred dollars a month, you have a decent job over there and don't send a cent!"), but as years passed -and our mom passed away- he became a more mature person, understood what I meant, and has dutifully been paying, little by little, his overdue half over the past three years.