What if its both and the gith artifact holds her real memory/powers
It doesn't.
Take a look to know what is the artifact:
the artifact is a prison for a Githyanki General.
Which datamining thread confirms that the artefact is a prison for a githyanki general? (Gith herself?) I know there was a lot of speculation about it being the infernal puzzle box containing the contract between Tiamat and Gith.
Reddit, someone posted the script notes for her scene when you don't recruit her and she show up at the camp. It mention what it is and it really should be under spoiler tag for this thread. This is not in-game information.
