Thank you all for responding so graciously to my mother's post asking whether she should fight this cancer or not.
You were all correct, she is very spunky and she decided to go ahead with the surgery. Luckily, the consult from Hopkins, her alma mater, came through before surgery saying that they agreed with her treatment. Also we managed to talk with a co-worker's husband who had had the surgery 9 years ago which gave her more confidence that it was survivable.
Surgery went very smoothly, she lost only 2 teeth and they got clear margins. She came home 2 days later (she lives alone but the 3 of us children live nearby and look in frequently). She just had the packing removed yesterday and is feeling well and looking forward to being able to eat all foods again.
We don't know yet about her singing voice but her speaking sounds the same and I presume the slight lisp she has will go away as she gets used to the obturator.
Now she is afraid of having to take the obturator out herself but I'm sure she will learn with practice.

We all feel very blessed and your posts helped a great deal.
Thank you