hi welcome to HCM
i had gone through your query and understand your concerns. i would come up with the possibility of BPPV;Benign Paroxysmal Positional Vertigo
may be the cause for your mother sufferings.
Dix-Hallpike maneuver may confirm the diagnosis.
consult your local physician for correct diagnosis of the case and remedy to fit her complaints
I hope this is helpful for you, thank you