Answered by Shaykh Amjad Rasheed
Is it permissible for woman to give a little bit of her husband’s money in charity in his absence?
It is permissible for a woman to give charity from her husband’s wealth if:
(1) he explicitly gives her permission to do so, or
(2) he hasn’t given permission but she knows that he won’t mind her doing so.
If, however, he neither gives her [h: explicit] permission nor does she know that he won’t mind her doing so, then it is unlawful for her to give any portion of his wealth in charity, as Imam Nawawi says in al-Majmu (6.244). He then goes on to say,
“This is how al-Sarakhsi, others from among our companions, and other scholars besides them have mentioned this issue. This ruling is binding and hadiths that have been transmitted in this regard are interpreted according to it.”