Sorry to hear of your mom's diagnosis. I would give her some time to process the news. Its a lot to take in, as I am sure you know. My dad was initially against a lot of treatments but eventually came around. After my dad had his second surgery, he drooled a lot, too. His medical oncologist said there are pills one can take to dry up saliva, which stroke patients use sometimes. They also talked about filler injections to plump up his lip, because he couldn't feel it or move it right after surgery and saliva and food would just dribble out all day. In the hospital, he held gauze between his lips to catch it, and that seemed to help. The nurses also put Vaseline on his chin to protect his skin.