Vowing to fast on Mondays and Thursdays as long as she can

Q: My paternal aunt vowed to fast every Monday and Thursday as long as she is able to do so. Now that the blessed month of Ramadan is approaching, may the Arab and Islamic nation have many happy returns on the occasion, what should she do concerning her vow, given that she started to fast following the past Ramadan, 1401 A.H.? Should she make up for each Monday and Thursday in Ramadan? Kindly point this out to me, so that I can explain it to her in detail, as she asked me to seek your Fatwa. Allah is in the help of a slave as long as he is in the help of his brother. May Allah protect you.

A: She should not fast on Mondays and Thursdays in Ramadan with the intention of fulfilling her vow, nor should she make up for them or expiate for them. (Part No. 23; Page No. 269) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.