Lots of hugs, marle and prayers for you and Megan as you continue on. Whether using or not, I think your position is right on - she's never going to learn if you pick up the pieces after her.
I was doing some cleaning over the weekend and came across some bank statements from 5 years ago. I was amazed at how many of the bills I was paying then that were not mine. It's no wonder it took my daughter so long to learn some fiscal responsibility. Words you spoke here helped me stop bailing her out. You said when you paid your Megan's bills, it only made her credit good so everyone wanted to loan her more money!
Hugs