What is the ruling of Islamic law regarding a woman who inherited a sum of money with her sister, then wanted to return her share and demand a house, knowing that her brothers are still paying monthly sums to her sister, and that her husband is deceased and she has adult, working children?

If the woman received the disputed amount as her share of the inheritance based on a consensual division, or a lottery, or a settlement, and she was an adult and of sound mind, then she is not entitled to revoke or annul the division unless it becomes evident that there was a clear mistake or gross deception in the division. In such a case, she has the right to demand an investigation into the matter and to annul the division. The fact that they pay her sister or that they are married does not affect the ruling. In such cases, reconciliation and forgiveness among siblings are advised, as Allah Almighty says: "And to forgo it is nearer to righteousness. And do not forget graciousness among yourselves. Indeed, Allah is Seeing of what you do." (Al-Baqarah: 237).