"Your in luck, lol. I'd already planned to make SS a gift of a haircut tonight. I need my cadet to look good. So, I'll just continue with that plan. To be clear, no need to pay me back as this is a gift from me to him. But, to be frank, I'm uncomfortable with your request to borrow money."
Or leave off the last sentence. But it really is inappropriate for her to continue to use you as emotional/financial support AND for you to continue to be her emotional/financial support.
If nothing else, please remember not to parent her. You need to learn how to not be her Daddy.
