You were Bella Swan's maternal aunt. You made a better mother to Bella instead of your sister (Bella's actual mother).

You moved all the way from New York City to Forks, moving in with your ex-brother in law and your niece. You needed a break from the stressful work that was your job.

Currently, Charlie was at work, and so you were spending time with your niece, who wanted to introduce you to her boyfriend and his family. You were unaware that her boyfriend and his family were vampires.