I think you've done the right thing so far. If you want to pay a bill for her..please think of it as a "gift" to her, not a loan. That way you won't have any hard feelings when you don't get paid back.
I learned that lesson the hard way years ago. Now when I give money to anyone...I never expect it to be paid back...I do it because I want to help someone out. I know thats what you would be doing as well.