The wizard Anska is stalking me, I think she wants the mask of Vokun. Not sure if I left it at the College. I can deal with this but I notice that sometimes she glows and sometimes not.

Any idea why this is ? I may just kill her anyway.

Did your character give her the scroll from the chamber with the Word Wall in Highgate Ruins yet, She is probably glowing from casting a shield spell.
I have a character who would appreciate Anska as a follower.

^^

She tells you at the start of the dungeon that you can have anything and everything BUT the scroll. The game prompts you to give her the scroll when you pick it up.