Is she injured? Hasn't worked a match since TakeOver
I'm pretty sure she isn't injured. For two weeks in December, she was on vacation in Japan to visit her sister (and family) and take part in the Yoko Bito farewell show. She came back to America a few days before the tapings started.
Right now I'm going to assume she isn't needed for anything, but if she's not part of the February tapings, I'm going to assume WWE doesn't have much interest in pushing her anymore. Because her only logical feuds are with Shayna and Ember right now.
That being said, they added another set of tapings for early March back at Full Sail. Originally they weren't supposed to go back until April, but someone in NXT probably pointed out it wasn't a great idea to lock down your entire New Orleans Takeover card in February.
Ideally Kairi will be in the title hunt at Takeover: New Orleans, but once Candice LaRae actually debuts on the main NXT roster (instead of dark matches and house shows), all bets are off, because anyone who is a babyface not named Candice LaRae will get booed/no reaction if they are in the Women's Title hunt.
For what its worth, the general thing I've heard about the latest set of tapings in terms of Women's Wrestling is that its basically a bunch of students/new talents getting their chops, and that the quality of the wrestling was incredibly low at best.
can confirm this, but I don't think the Iconic Duo has been utilized at all lately either. And I don't think they are getting called up at the Rumble. Probably a one off appearance. You don't see too many NXT callups on the Road to Wrestlemania.