You're good. Let her make mistakes and face the consequences of them. You saving the day sets a dangerous precedent.
Your kids will be okay, and you will be okay as long as you don't allow any attempts by her to blame YOU for HER money problems to get through your defensive shield. If she does lash out, it is just in anger that she doesn't know how to handle and direct in an emotionally healthy manner. Be above that.
-PM
M:12y - BD:12/11 - D:6/13 - 4Ds
"The ultimate measure of a man is not where he stands in moments of comfort and convenience, but where he stands at times of challenge and controversy." -MLK Jr.