Re: thick thick nails ... help!
With my RB kitty Pyxl, the vet used to point her thickened claws out to his vet tech, and say "see this is what I was talking about". At first I thought he meant is had something to do with age, as Pyxl was 16 when he started seeing her. I suspect that thickening of the nails may be indicative of a health condition though, as one of my new kitties, Major Tom, has a few claws that are quite thick, and appear to have been damaged during his life (1.5 years) as an alley cat.
1. Get a scratching post, you may need to "show" her how to use it by scratching it yourself (never force or hold her paws onto it, cats are contrary, she'll avoid it just to tick you off then!), but she should actually enjoy it. If she doesn't, just know that some cats prefer vertical scratching surfaces and some prefer horizontal surfaces. Carpets are okay, but not really rough enough to do what needs to be done. In the wild (wilds of the back yard, anyways) cats will use trees, wooden fences, Adirondack chair legs, etc, as scratching posts.
2. She's old enough for a Senior Wellness Check-up (to include a senior blood panel), while there the vet can inspect her claws, trim them, and advise you. (cautionary, if the vet recommends declawing, do some research first, you really need to know what you are getting into with that). But with the senior check-up, the vet will be able to tell you if it is a health issue.