She is gorgeous!! It would suck to have her shaved but when it comes down to it, if her matts are tight and close to the shin you might not have an option. Good thing hair grows back.
I'm a dog groomer and had the opportunity to learn how to groom cats but passed on it for many reasons of my own. One being that I like how my hands and face look. LOL Another being that dogs skin is 7 times thinner than humans and cats skin is thinner than dogs. I've seen cats get nicked with clippers and their skin pretty much tears like paper. It can be pretty scary at times shaving matts from armpits of a wiggly dog, I can't imagine shaving that area on a cat. So I don't recommend letting just anyone with scissors or clippers around your cat.
If the matts aren't really tight and against the skin you can use a metal grooming comb to pick the matts out. Hold the hair next to the skin so not to pull her skin while using the comb on its end to pick at the matt. If it seems like you're torturing her, I'd find a really good cat groomer (that will pay the vet bill if she's injured) and have her shaved. Start over with brushing and combing her as hair grows back.
The shed ender is an awesome tool. I believe stores like Petco and PetSmart do carry a similar tool. The Furminator is another one. I like the one with a wooden handle called a shedding blade. There are different types of teeth I would get the wide teeth for your kitty if you were going to get one. But I think using a metal would be best since you can get it through all that thick fur.