When I was mentally in I would still give money to my DF'ed close family member in need.
I would sit down with them and determine whether they are really in need or do they just want a bailout of their poor decisions. You could ask them "If I was in need would you help me?" Try to reach their heart.
Refusing to help them because of the way they treat your husband will only enhance their indoctrinated world-view. If you are vindictive at all it will only strengthen their confidence that they are "doing the right thing for Jehovah"
Help them out but use this opportunity to open a dialogue, in love. Love hopes all things and love never fails