Kitty,
I was in a very similar situation in my last job. I was the supervisor for a woman who was ill a great deal of the time. I always worked with her to make sure she had the time off she needed and saw that she got sick pay even when she had none accrued so she wouldn't suffer financially. After awhile her absences got so frequent that HR forced me to put her on a verbal warning. Two days later she came into work, dropped a letter in my lap, said "I quit", and stormed out. I never saw her again. The letter said basically that I was too overbaring and hard to work for and that the company had treated her horribly and she felt that she had no choice but to quit. I was devastated by that after all I had gone thru to try and help her.

The bottom line here is that you did the best could to do right by this person. You can't control the actions of another person. I know it hurts when someone that you've gone out of your way to help does something like this, but it will pass. You are not a bad judge of character, it just sounds like you were taken advantage of, that's her bad. Being kind to other people is never a bad thing.

bp

"I am ready to meet my Maker. Whether my Maker is prepared for the great ordeal of meeting me is another matter."