Ask yourself "would H be there for me if the shoes were on the other feet?"
I'm not even sure that's the right question, because even if they WOULD -- or even, as you said, you'd do it for a friend -- it would still enable further bad behavior and do nothing to help them become more accountable for their irresponsible actions.
No, the better question is, "What does this do to REALLY help this person that I love get the help they need, and what does it teach my children about chracter if I enable the bad behavior over and over again?"
