Hugs Patch, I hope you can find the balance between support while she does what she needs to do and establishing boundaries to maintain your sanity and serenity. So tough when there is a little one involved.
I've found it easier to discuss my boundaries when i am not annoyed. If I can do so calmly and matter of factly, then my family member doesn't get defensive. Too often i have laid out rules in anger with no success.
We can't control what they do with their time or money, but you certainly can establish boundaries for how much assistance you provide and how often.
Hugs.