Glad you're having a great vacation!
If Gemma is in fact matted when you return, I've found (having gone through the same thing) that it's easier to take a few days to finish combing and de-matting rather than trying to cram it all into one marathon session (if, that is, you decide against the quick fix of shaving!). Just pick an area to do for the day - side, belly, back - and when that's done, pretend that the rest isn't bugging the heck out of you and let her, and you, rest for a day before tackling the next section
. I'm sure she will be fine though, it sounds like your mom is taking very good care of her!