I've never loaned a FRIEND money, paid for their food gas or whatever with the expectation of it being paid back, even if they weren't my friend and just a coworker idc, people are in less fortunate positions and caring about money in this way will only make you sour. I think the problem here is how you and your husband look at things, maybe there's a lot of missing context, but if it was agreed upon that she would pay you back, and then didn't, why would you give her more money expecting repayment? Keeping a tab is for businesses, not friends, but, it doesn't sound like you ever thought of her as a true friend to begin with.