Wow Lola, I kept up with your other threads too.
My view is that her DHs family simply canot do without him sending over money, whilst you are expected to do. Not exactly fair is it. Goose, gander etc. Don't give her your savings! Why should you save up to improve your own future just to have someone else blow it on frigging £10,000 debt THEY accrued on a credit card? I take it the DH benefited from the debts on this card?
I know you want to help, it is only natural. However, this passive aggressive behaviour is again, not fair on you. Why should you subsidise HIS family which is essentially what you would be doing if you pay give over your savings or take a loan. It's a bloody cheek if you ask me!!
I think you done as much as you could by very kindly offering to call Visa for her, but no, that still wasn't enough. Only hard cash will do, then what happens in May and June and so on? It won't stop after one payment. If she actually got off her arse and called them and explained the situation, they would have to come to some sort of agreement, after all, they can't get blood out of a stone.
This DH of hers has a lot to answer for and so does she for guilting you into this position .
Sorry for being harsh in my post, it is wholly directed towards your mother and her DH. I feel really bad for you that you are in this position Just out of interest what kinds of things did she buy with the Visa?