Vowing to finish reciting the Qur'an once every month and not doing at some months

Q 3: She vowed to make a Khatmah (completion of one reading of the whole Qur'an) every month for life, after her labor. Now, after the passage of seven years, she has made only six Khatmahs. What is the ruling on this? I need a solution.

A: She should fulfill the said vow, for it is a vow to do an act of worship, and the Prophet (peace be upon him) commanded us to fulfill vows when he said, Whoever vows to obey Allah should obey Him. She has to make up, in the future, for the Khatmahs she abandoned. We ask Allah to guide you and grant you success.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.