daud i would suggest u consult with some aalim or mufti on this matter i know the answer to ur Q but im afraid of giving my opinion on this matter.

in most of the cases mothers health is given 1st priority when such situation arises.but consulting with an islamic scholar explaning him all the details of the mother ,her health situation now and in the past etc and etc ......would be more helpful

i wouldnt recommend u to act on some ones opinion on ql.

those ismalic scholar have spend 15 to 18 yrs of their life studying sharia laws and they are always their to serve us.

sheikh osama(from lucknow) very well known aaalim serving as an imam at al-attiya masjid in industrial area m sure he will be able to help

may ALLAH give her best of the health, prosperity and make her prepare for the situation which is best for her interest.