I care for some else's child
why do you care for some else's child?
There is no particular reason for it.
It is unfair to care for another's kids. However, the kids shouldn't suffer for neglectful parents. You providing them care is something to be proud of.
I'm glad you realise that I am helping them.
It's nice to see how much you care for children. A world would be a better place if there were more people like you.