Is the husband obligated to financially assist the wife's mother if she is in need, or does the wife have the right to dispose of her husband's money to give it to her mother?

The wife's effort to help her mother is commendable. However, she must obey her husband if he forbids her from working, and he is not obligated to grant her permission. There is no harm in asking him for money to help her mother; and even though he is not obligated to give it, he should do so out of generosity. The wife should strive to honor and assist her mother as much as she can, and she should encourage her siblings to do the same, clarifying to them that financially supporting poor parents is an obligation upon capable children, both male and female, as agreed upon by scholars.