My friend had this problem & found a small tool that helped. It was a plastic hook with a captive blade within the hook. It's used to split mats lengthways, which really helps with the removal. I think it's a dog grooming tool made by 'mikki'. You could carry on using the scissors for the same thing - always cut away from the skin down the length of the hair, towards the ends of the hairs. Mats have a tendency to get bigger & bigger, so any part removal is good. The smaller the mat the easier it is to finally remove entirely. The tool had the advantages of being small enough to conceal within the hand, very safe & used one handed, unlike scissors. It would also be a good idea to appeal to her appetite & do your daily gooming before/at feeding time or with the 'help' of a few tasty treats. Good luck.