Does the vow made by the grandmother—to bake cakes and distribute them to worshippers every Eid—lapse with her death, or must it be fulfilled on her behalf?

The vow that the grandmother committed to ended with her death because it was [binding] during her lifetime and at its [appointed] time. She did not make any bequest, and her heirs are not responsible for anything concerning this vow, as the obligation ceases with death.