Is a mother's prayer for her disabled daughter to die before her, or on the same day as her death, for fear of her being humiliated after the mother's death, considered forbidden or a sin?

It is not permissible for a mother to supplicate against her daughter and wish for her death, even if it is due to or out of fear of the pandemic, because the Prophet, peace be upon him, forbade supplicating against children.

Instead, one should frequently supplicate for her well-being, as the Prophet, peace be upon him, said: "Ask Allah for pardon and well-being, for no one has been given anything better than well-being after certainty." And supplicate for her with words such as: "O Allah, I entrust my daughter to You," for Allah preserves what is entrusted to Him.

The righteousness and piety of parents preserve their children from evil, as Allah Almighty said: "And let those [parents] fear who, if they left behind them weak offspring, would fear for them. So let them fear Allah and speak words of uprightness."