Is the female questioner obligated to offer expiation for her uncle's oath, given that she was the cause of his breaking it, and knowing that he will not expiate his oath?

Giving the uncle the keys is considered a breach of his oath, and it is better if it entails good or benefit. He alone must offer expiation for breaching the oath, based on the Prophet's (peace and blessings be upon him) saying: "By Allah, if Allah wills, I will not swear an oath and then see something else better than it, except that I expiate for my oath and do that which is better." If someone else causes him to breach his oath, the expiation is still on him. He should be advised of the obligation to offer expiation if he has not already done so. Oaths must be preserved, and one should not swear by Allah excessively except when necessary, as Allah Almighty says: (And do not make [the name of] Allah an excuse in your oaths) and (And do not obey every [worthless] swearer).