What is the ruling on abandoning prayer and prompting the Shahada for someone who died after a four-day coma?

There is no sin upon the deceased woman for not having prayed due to fainting, as many scholars hold that the unconscious person is not accountable. Some of them hold that making up the prayers is obligatory if consciousness is regained. Based on both opinions, nothing is incumbent upon her.

Her children should supplicate for her frequently and give charity on her behalf.