Laura
I got a severe laryngitis last year (it lasted for 6 weeks - no voice) and was found to have GERD, gastric-esophageal reflux disease and that my stomach acids were bubbling up my esophagus and getting on my vocal cords... try doing an internet search on larygitis and you will see the number of references... unless your mother was at a sporting event or something like that screaming and yelling, there is a good chance that it is GERD. If it does not go away soon, she should get to a GI doc. In the meantime, have her elevate the head of her bed and don't eat anything for at least 3 hours before going to bed. good luck and tell her happy birthday.