This is very beautiful work, it's very cute. <3
The pose is cute as well, though here's some advice for if you ever do it again.
Now from what I can see is that (no offense.) the toes on your paws seem to be either missing or just plain un-natural.
I'd suggest you look up more on how paws work for cats, and how they look when they are drawn, but you did a wonderful job with them. I say this because it's hard to place the toes on paws for me, as well. x'D
Also, I think you need to work a little bit on your shading, because there seems to be more light on the tail rather than her back, which is more likely closer to the light(from what I can see of with the way the shading is laid out).
And I noticed there wasn't much shading in the white areas on your character, you might need to work on that too.
Just one last thing,
You should try to make the greenery around her more natural, like maybe a few bits of moss covering where her body meets with the nest. And maybe a few little grasses, instead of just a plain green floor.
I hope this helps you,
Over all I honestly think you did a very nice job <3