He's charming—that is Jenna's first impression of him. He knows just what to say to make her feel at ease, and he does so in such a natural way that she actually does feel at ease. For the first time, she doesn't wonder what's behind the façade; she doesn't think it's too good to be true, doesn't think he could be using her for any nefarious purpose.
When Jenna first meets Elijah, she just thinks he's a damn good sweet talker who wants to (for reasons she'll never understand) write about Mystic Falls.
-x-
She notices the way Alaric glares at him when she's showing him the old Fell property. She just doesn't understand why.
Elijah's been a perfect gentleman with her and he's never once shown any indication of wanting any sort of relationship with her.
A part of her enjoys the jealousy in Alaric's eyes, so she stands marginally closer to Elijah than necessary, holds his gaze for a few seconds longer than required to be polite, and smiles serenely when he talks.
Outwardly, she plays the innocent, but Elijah's knowing glance tells her wordlessly that he sees right through her.
-x-
Jenna wonders why Damon seems to hate Elijah so much.
Elijah, on the other hand, seems amused by the eldest Salvatore's antics, but they start to grate on Jenna's nerves throughout dinner.
He must have gotten fed up with Damon's snide comments and rude gestures, though, for Alaric—after the guys had all been absent for a while and it had just been her and Andie eating desert—later tells Jenna he's left.
She's surprised Elijah didn't tell her himself, though. He seemed the type to say goodbye in person.
-x-
When Jenna finds out about vampires, she's apprehensive to trust anyone again. She obeys Stefan only because it seems safer than staying around the man who is so obviously not Alaric. But Stefan is a vampire, and she doesn't trust him as far as she can throw him—and Jenna's never been one for sports.
She can't trust Alaric because he isn't there anymore. She can't trust Damon because she barely trusted him when she thought he was human. And for all she loves her niece and nephew, she's been lied to too many times to believe anything from their mouths without getting a second opinion.
But then Elijah's in the boarding house and Jenna's smiling through her seemingly endless bout of tears.
-x-
He tells her the truth and doesn't spare her anything. Jenna knows he's a vampire, one of the oldest, really; and she knows he had originally planned on sacrificing Elena. She knows all of this, and yet she sits next to him in the Salvatore boarding house and asks him which century he liked best.
He still says all the right things, laughs at all the right moments. His hand rests softly on her knee, and he tells her about the 1700s.
It's easy to like Elijah, she realizes; and when she glances over at Elena and Stefan and Damon, she thinks she's beginning to understand.