I'd like to start out by acknowledging all the good. The shape and anatomy are correct. There is only one thing that I think could use some improvement: the paws.
Mainly the front paws, though. They just look like they're fit if she were standing, since they look firmly planted. I like how you can see the paw-pads, as well as the thumb. With the top-hind paw, it also looks planted, but that's just about it. That's basically the only thing that, I could see, that could use some work.
I'd like to again say that I'm very impressed you did almost all of this without reference! Keep it up!
The anatomy on this is very well. The figure is 3-D and easy to read. It is an AMAZING sketch! The lines are so.. Delicate and properly placed. The eyes let you know, How she is. and her attitude. Those details are amazing. I love it. The only think I think that could be improved is the tail. It looks a tad.. Short. Hmm. Maybe give it a bit of a length, Eh? Well. That's my opinion. I still think this is a gorgeous piece of work. As always. Your work is ALWAYS impressive. Keep it up, Loving it alot!