AIR Force NAF 401K Vesting

My wife worked at the child development center as an Air Force NAF employee from November 2018 – September 2021 and left to be a SAHM when our daughter was born. She was contributing to a 401K when she worked there that has been sitting in a targeted 2055 retirement fund ever since she left and she never made any changes to the plan just sticking with what she initially signed up for. We are now wanting to roll her 401k over to her IRA that she has with Schwab, but looking at her most recent 401k statement, it shows the total balance is $5,370.36 but the vested balance is only $3,068.39. I'm not sure how long the vesting period was for the NAF 401k plan, but assuming she left before the full vesting period was over, wouldn't it automatically subtract the non vested amount from her 401k when she quit? Why is it still showing a large portion of her account isn't vested even though she hasn't worked there in almost 3 years? What would happen if we tried to transfer this account to her Schwab IRA? Thanks!