What is the position of a wife who paid off her husband's debts from her own money after he faced financial difficulties, and what is incumbent upon her Islamically?

The husband must spend on his wife, for Allah the Almighty said: "Men are the protectors and maintainers of women, because Allah has made some of them to excel others, and because they spend (on them) from their means." It is not permissible for him to take his wife's money unless she gives it willingly, for Allah the Almighty said: "But if they, of their own good pleasure, remit any part of it to you, take it, and enjoy it with good cheer and satisfaction."

The husband alone is responsible for repaying any debt he incurs. As for what the wife borrows for her sustenance while the husband is in hardship, she cannot claim it back from him, because he is not obligated to spend during hardship. However, if he was well-off at the time she borrowed it, she can claim it back from him. It is commendable for a wealthy wife to help her poor husband, and she will be rewarded for that.