Can she give charity from her housekeeping money without her husband’s knowledge?

No File Exists
Check below answers in case you are looking for other related questions:
Wife and children eating from the husband’s haraam earnings
Her husband has left Islam; is she entitled to maintenance during the 'iddah period?

No File Exists
Related Answers:
Wife disposing of her own money without her husband’s knowledge
Does a son have to spend on his father even if he is rich?
Definition of miserliness according to Islamic teachings
Wife and children eating from the husband’s haraam earnings
Her husband has left Islam; is she entitled to maintenance during the 'iddah period?

Recommended answers for you:
Veil Between Allah and His Slaves Lifted at Time of Breaking Fast
Ruling on dealing with mortgages in a non-Muslim country
The Hadeeth About Saying “Allahumma ajirni min al-nar” Seven Times
What is to be said in the Tashahhud of a two-rak’ah prayer?
Rulings on the mourning of a woman whose husband has died