Is it permissible to abandon a voluntary fast if it leads to weakness in physical and cognitive performance, and causes annoyance to one's parents?

Since fasting is not obligatory, one should obey the mother in not fasting, especially if she has a valid reason, such as her compassion for the daughter's weakness due to fasting. Obedience to parents is obligatory in matters that are not sinful and takes precedence over recommended acts. It is stated in the Hadith (definition) Qudsi: "My servant does not draw near to Me with anything more beloved to Me than what I have enjoined upon him." The Permanent Committee for Scholarly Research and Ifta' and Ibn Baz have issued fatwas regarding the obligation to obey parents in not observing voluntary fasts. Whoever refrains from voluntary fasting out of obedience to his mother, it is hoped that he will be credited with the full reward of fasting. If fasting causes hardship and weakens one from other acts of worship, such as reading the Qur'an, then breaking the fast may be better, even if the mother does not command it.