Vowing to protect the Power Stone on Xandar. Yeah, that went well.
Will She Be Back?
Doutbful. Though we didn't see it happen on screen, you can bet the Nova Corps stood up to Thanos the same way they stood up to Ronan and were rewarded for their defiance the same way everyone who stands up to Thanos is - with death.
Assumptions aside, this would also be a great way to introduce Nova as a stand-alone character, so we MAY get to see a flashback (or time jump back) to the destruction of Xandar in a Nova movie at some point. Which might give Glenn Close a chance to return as the character.