It is narrated from Hazrat Aamir bin Mus'ab that Hazrat Aisha (may Allah be pleased with her) performed i'tikaf in place of her brother after his death.

12972 - Jarir narrated from Layth who said: Tawus was asked about a woman who died while she was required to perform i'tikaf for a year in the Sacred Mosque, and she had (four) (1) (sons) (2), all of whom wished to fulfill it on her behalf. Tawus said: All four of you should perform i'tikaf in the Sacred Mosque for three months and fast.

It is narrated from Ubaidullah bin Abdullah bin Utbah that a woman had vowed to observe i'tikaf for ten days, but she passed away and could not perform the i'tikaf. Ibn Abbas (may Allah be pleased with them) said: Observe i'tikaf on behalf of your mother.

Ibrahim says that the missed I'tikaf should not be made up on behalf of the deceased.

Hazrat Tawus, regarding a vow made for a deceased person, says that a decision will be made among his heirs, and if someone has fasts of a year due upon him, then if the heirs wish, they may observe the fasts; each of the heirs will observe three months of fasting.