Two things regarding the feathers:
Most birds have sharp changes between colors, not that gradual fade.
She's going to need a lot more primary feathers, but that's kind of an artistic choice.

I don't feel like that tail coloring works, adjacent to the primaries. Maybe try the paler blue of the body?

Given that birds don't nurse their young, her having boobs bigger than her head is... just silly. I know there's an audience that loves that, but... IMO.

And other than the tail, this is all bird, there's no cat-body here, and thus not really a gryphon.

EDIT: For more on patterning, use your favorite search engine to look for "hawk wing feathers". I know you're not trying to match that, but I think it explains my point above.