There is nothing wrong with your anyone’s Hajj on behalf of a deceased. As long as the former has performed their obligatory Hajj, they can perform Hajj on behalf of the deceased.
Sheikh `Abdul Khaliq Hassan Ash-Shareef stated,
Anyone can perform Hajj on behalf of your deceased and accordingly if they perform of `Umrah on someone’s behalf, this `Umrah is acceptable, Allah willing. Thus, the deceased will receive the reward of the `Umrah and the representative will gain a similar reward that does not reduce the deceased’s reward.
May Allah accept all your good deeds!