[Captain Nash]

Yes, that's Moonstar. She's also gone by the name Mirage or also Dani Moonstar (kinda obvious code name since it's her name.). She was one of the original new mutants but left midway through the run. Hitched up with 90's X-Force after a turn as a double agent on a villains team, about 2/3rds of the way through that run. Kind of been in and out of the spot light ever since, depowered in 2004 and while never getting her powers back she's still been at least a background character over the last 10 years. She also has valkyrie powers gifted by Hela/Asgard but I think some writers tend to forget that.

Honestly I think given her de-powered state she would make an excellent Avenger, as she has tracking ability honed by her Cheyenne upbringing.

Just my opinion here but she's to me the third most important new Mutant after Cannonball and Magik, though I know some will disagree, which is fine.