Is it permissible for the wife to save from the money her husband gives her for her personal expenses, with the intention of saving for the future?

If a husband gives his wife money for her personal expenses, there is no harm in her saving some of it, but she should inform him. The permissibility of saving for need is evidenced by the actions of Yusuf (peace be upon him) in his economic plan to save food, and by the Prophet (peace be upon him) saving a year's worth of provisions for his family.