What was your initial reaction when she started giving you that leave now or I'll kill you with my powerful pinky attitude? At level 63 I decided to attack her with my orc. Although she had lots of health she ran to the corner immediately, cowering in fear... So much for her tough talk.

Who took the books and left the elf to The Caller? Do you think she's wanting to keep him because they're both High Elves?

I never manage to save the elf anyway.

First try: I opened the gate, he came out immediatly initiated conversation, aggroed the mage and got us both killed in conversation
Second try: I saved us both, but he then spent 6 minutes shooting lightning at the cage with the dogs in while fire atronachs gave him some red hot rear action
Third try: He kept aggoring dozens of foes at a time AND THEIR SUMMONS.
Forth try: You are officially http://tvtropes.org/pmwiki/pmwiki.php/Main/TooDumbToLive screw this

at level 63 she should be a pushover lol. i couldn't leave the elf with her, naivte shouldn't be punished by death. on a level 20-ish mage i had, the elf was actually useful in the fight. he summoned, i summoned, she summoned, it was a great cage match.

if you don't bring the elf (on another playthrough i told him to get lost, i can handle it) you can actually use a speech check to take the books and leave. the only quest i ran into where a speech check was used (and used properly). i passed the speech check and killed her anyway.

after all the attitude she gives you, there was no way i was leaving her alive. this is one of the better quests in the game just because there are multiple ways of solving: speech check, kill her with the elf, take her solo, give her the elf and take the books. quests like these allow for role play.