Yeah. They could've looked at the old issues of Wolverine and draw her bones claws like that.
Contrasting the surface detail I do think they are bone. Also, don't forget that she has a claw sharpener (Cabal drew it in one of his issues) so she probably shaped her claws.
When/how did Gabby get metal claws? I must have missed it along the way.
I think it's just a mistake on the artist's part.
Doctor Strange: "You are the right person to replace Logan."
X-23: "I know there are people who disapprove... Guys on the Internet mainly."
(All-New Wolverine #4)