Am I sinful if I do not obey my mother, who insisted that I eat food containing forbidden nutmeg? And must I ask her every time about its presence in the food?

Scholars have differed on the ruling of using nutmeg in food. Some have permitted a small amount, while others have prohibited it. Ibn Abidin, Al-Ramli, and Ibn Daqeeq al-Eid considered it forbidden. On the other hand, Al-Hattab, Al-Manqur, Al-Azim Abadi, Al-Zuhayli, and the Symposium of the Islamic Organization for Medical Sciences permitted a small amount, as long as it does not lead to intoxication or stupefaction.

If your mother uses a small amount of it, a group of scholars has permitted this. However, if you believe it to be forbidden, you are not obliged to obey your mother in doing what you consider to be forbidden. It is advised to be diplomatic and avoid angering your mother, such as by pretending to eat. You do not need to ask her every time unless she predominantly uses it. In general, it is obligatory to honor and be kind to one's mother.