To echo Rebelfighter, this does happen in the nonJW world but it doesn't have the extremely ANNOYING additional feature of coming from people who believe they are morally superior to you and shun you to prove it (when money isn't involved, of course). Strong Haiku is also correct about how it often plays out (you fund their fun while making cutbacks to do so).
It's ultimately your decision but I'd say do only what you feel comfortable with. Don't think it will win you any points. Don't lend money you can't afford to lose. As a general rule, think of it as a gift, not a loan no matter how much they say they'll pay you back... broke and financially irresponsible people are struggling to pay their own bills. Paying back someone, especially someone they don't respect, is not high on the list of priorities. I know it's hard to say no to family, so do what you're comfortable with and don't feel guilty about drawing the line there. All the best :)