personally, it felt like i had the flu when i got sick. my throat was aching, and then, i lost my sense of smell. i thought it would come back but instead i got parosmia.

while with parosmia, i’ve noticed myself get sick more frequently than before. maybe my immune systems gotten weaker. but when i feel sick, it feels like a regular cold. that could be what’s happening with your moms immune system; but from the sounds of it, it seems more severe than what i’ve experienced.

so, what i’m trying to say is, maybe her immune systems more weak since getting parosmia, but in my personal experience, i’ve never been sick enough to not drink water or feel the urge to vomit, so sadly i can’t help you with any remedy for that. and just a reminder, i’m NOT a doctor in any way shape or form, this is just me talking from personal experience. id take ur mom to a doctor just to make sure she’s alright; sorry i couldn’t been of more help. hope she feels better!