Asatira is a Dunmer/Dark Elf NPC and follower. She is mage from house Telvanni and is a potential wife as well as a battle mage, specialising in destruction and conjuration (though not necromancy).

She can be found in the Midden at the College of Winterhold, by the Atronach Forge.
She starts out at level 60, and will level up with the player.

From what I gather, she doesn’t appear before finishing the College main quest (due to the entire area developing into a battleground before this quest is completed).

If there are any problems let me know and I will see if I can fix it.

You don't need any of the add-ons but you may need the hair mod:
Hair by Apachii: http://skyrim.nexusmods.com/mods/10168
For anyone who may be wondering, the robes are part of a comprehensive clothing retexture mod which is not required. Retexture by MissObsidienne: http://skyrim.nexusmods.com/mods/19826