Is it permissible for a woman to give from her own money to her orphaned sisters without her husband's knowledge, if the husband is well-off and does not help his wife's needy relatives?

Sponsoring an orphan is a great act of devotion. If the orphan is a relative, the reward is even greater, as the Prophet, peace and blessings be upon him, said: "Charity given to a poor person is charity, and to a relative, it is two things: charity and maintaining kinship ties." If you are the owner of the money, you may dispose of it by spending on your mother and orphaned sisters without your husband's knowledge. However, if the money belongs to your husband, you may not dispose of it without his permission. You should convince him that the reward will be doubled because they are orphans and relatives.