She left because she was being harassed. <br />
<a href="http://www.experienceproject.com/question-answer/Why-Did-I-Convince-Her-To-Stay/2794169?action=answer" target="ep_blank">EP Link</a>
I don't know. Sorry. :/
She didn't delete her account.. she changed her profile name... I can't remember it though
it's weird.. i remember seeing her in my circle yesterday.. but when I looked few minutes before, couldn't seem to find her... may be You're right that she probably deleted her account..