Hawzah News Agency – If a husband divorces his wife while he is ill and dies before the expiry of twelve lunar months, his wife inherits from him on fulfilment of three conditions [as below], irrespective of whether the divorce was revocable or irrevocable.

1. During this time, she has not married another man. If she has married another man, she does not inherit, although the recommended precaution (al-iḥtiyāṭ al-mustaḥabb) is that they [the ex-wife and the heirs] arrive at a settlement.
2. The divorce has not taken place at the request of the wife, otherwise she does not inherit, irrespective of whether she paid her husband something to divorce her or not.
3. The husband died with the same illness he had when he divorced her, and he died due to that illness or some other cause. Therefore, if the husband recovers from that illness and dies later due to some other cause, the divorced wife does not inherit from him unless his death happened during the ʿiddah period of a revocable divorce.

Source: https://www.sistani.org/english/book/48/