Is it permissible for the children of a deceased, ill person who was unaware of breaking their fast in Ramadan and did not make up for the fasting due to their illness, to fast on their behalf?

If a person who was unconscious during Ramadan regains consciousness for a period that allows them to make up the fast, it becomes obligatory for them to do so. If they fail to do so, it is permissible for their guardians to fast on their behalf. However, if the unconsciousness persists until death, or if they regain consciousness for a period insufficient to make up the fast, then there is no obligation for them or their heirs to make up the fast.