This is how it works--if they ask for money, give what you can. And do NOT expect to be paid back. Actually you tell them not to pay you back. Those are the rules...
I'd add one more rule which a mentor of mine taught me years back. it's worked really well for me the few times I've invoked it, closed off unfinished unhappy business. If you have lent money to someone and they aren't paying you back as they promised, if it has gone on long enough and you find yourself resentful and angry about it, send them a note which says:
"With this note I forgive the debt of $xxx which you borrowed from me and have not paid back per our agreement. If at some time in the future you have the funds available, I request that you donate it to the non-profit charity of your choice in my name.
I now declare this transaction completed."
You'd be amazed how much better you'll feel taking that resentment off your unfinished business list! And it holds the borrower morally accountable at the same time as you are disconnecting from them. As I said, it has worked really well for me in a very few instances in the past, before I learned not to lend money to "friends."