What is the ruling regarding a wife who took money she found in her home, not knowing if it belonged to her deceased husband or his father, given that he did not leave her a single dinar?

The money found in the deceased husband's house is considered part of his estate, as it is fundamentally his property, and the possibility of it belonging to someone else does not alter this. This money is to be distributed among all his heirs according to each one's prescribed share in Islamic law, after any outstanding rights have been fulfilled, if applicable.