Get her a caffiene-free can of soda and some saltines.  Have her sip the soda and prop up on cushions on her left side.  She needs to be elevated.  She may have a hiatal hernia above her stomach like I do.  The esophagus is highest when you are laying on your left side.  The soda will clean out the hernia, if she has one, and clean it out.

Take her to the doctor and ask about Aciphex.  It is great stuff.  She will only have to take one tablet per day. 

Drinking water doesn't help.  Milk is better, the sugar in it, the lactose, cools down spice. 

Another thing, she shouldn't eat after 6 pm.  That way, her system will have enough time to digest before bed.  She shouldn't lay down for at least 3 hours before bed.  It also helps if she can get a wedge pillow to sleep on, or raise the head of her bed 6 inches. 

The reflux can cause scar tissue in her throat.  I have had to have my esophagus stretched.  It isn't painful, you are sedated.  One of the bad things is that food may become stuck in her throat.  I have had to have food extracted from my esophagus before. 

Take her to a good upper-GI doctor.  He is her best bet.  TheresaGHW

I have a simaliar problem, I cough up acid about 3 or 4 in the morning and imediatialy go to my lungs cloggeing them up. I usually take pepsid chewable about 3 and wait takes 20 minutes to clear up. i usually eat hot cereal before I go to bed so the acid will work on it tru the night if I do not this happens not a pretty sight.I had my esop. removed 5 years ago because of acid reflux, had Barret and arestriction growing in pipes , food clogged up would not go down or up, I can eat now but have these problems.when acid comes up it burns my troat and mouth just try eating some thing at night and prop up the front of the bed to keep acid down. I have been tru a lot and just lucky to be alive.try these and see what happens.