So my mom is freshly over covid, and complaining that she has an insatiable/unquenchable thirst and the roof of her mouth is white.

I was surprised to learn this is not an uncommon post-covid (and sometimes pre-covid) symptom.

Anyone know of a cure, or how long it lasts?

She can’t go an hour without drinking water now.

White mouth sounds like a fungal/yeast infection.

Why ask the mob? Why not get her to a doctor who can check her? There are trustworthy ones to consult.

Because competent medical doctors are few and far between.

As if the mob is a better source for reliable quality medical care?

Why ask the mob? Why not get her to a doctor who can check her? There are trustworthy ones to consult.

Can you recommend one?  We don’t know any trustworthy ones.

If you don't know a trustworthy doctor, ask an ER nurse.

They see not only the docs working in their ER, but get a good look at the responsiveness, demeanor and care of the docs who take "call," so have a pretty good eye for the good docs.

One caveat—whether urban or rural, ER nurses typically common things, so they do not have the training or experience in identifying or treating the exceptional cases. Sure, they see some "one off" sensational and weird cases (like the guys that put lightbulbs where they don't belong), but that does not translate into the acuмen necessary to handle the "sleeper" cases that require speedy insight and special handling (e.g., back pain that is a dissecting aneurysm, not the usual narcotic seekers complaining of back pain).

Water doesn't cure thrush.

So my mom is freshly over covid, and complaining that she has an insatiable/unquenchable thirst and the roof of her mouth is white.

I was surprised to learn this is not an uncommon post-covid (and sometimes pre-covid) symptom.

Anyone know of a cure, or how long it lasts?

She can’t go an hour without drinking water now.

according to WebMD, without knowing much else other what what you have said, she has HIV, candidiasis, or thrush.

this is my go-to natural healing website: earthclinic.com

they say milk of magnesia for adult thrush.

for candida, multiple remedy suggestions:
https://www.earthclinic.com/mobile/cures/candida-most-popular.html

candida is difficult to cure.  usually super low carb diet does the trick.

your mother may also have an electrolyte imbalance and is not absorbing her water properly.  adding electrolytes to her diet may balance itself out, but seeing a doctor is probably her best course of action.  try talking to the people at church and see who they recommend, then do your due diligence to research and even interview the doctor.  as an adult, I have interviewed every doctor I have ever gone to.