When Elena and Bonnie get to Abby's, they first meet up with the very-easy-on-the-eyes Jamie. He's not Abby's son, nor any blood relation (Elena makes woo-hoo eyes at Bonnie when they learn this). Jamie's dad was involved with Abby for a while, but ended up being a deadbeat, so when the dad took off, Abby took in Jamie. Wait, so Bonnie's deadbeat mother left her own daughter and then took on some other deadbeat's kid? Ouch, Bon. That's gotta sting. When Abby gets home, she gives Bonnie and Elena some more back story.
Abby and Miranda Gilbert (Elena's mom) were best friends. When Elena was three years old, Mikael the Vampire Vampire Slayer came to town, looking for the doppelganger. Abby tells Bonnie that she used up all her magic, and nearly died, to desiccate and entomb MtVVS, and save her BFF's little girl. Once Abby recovered and realized her magic was gone, she decided to stay away from Mystic Falls, and start a new life. I have to hand it to the show, here. They could have given Abby a noble reason for abandoning her child, but they decided to go for the pain. Ms. Wilson could have returned to her daughter. It seems she didn't stay away to protect Bonnie, or anything worthwhile. She made a selfish choice. Poor little Bon-Bon. (I do hope they don't negate this pain with some future explanation. This is a brave writing choice and enriches Bonnie's character.)
When Abby and Bonnie's conversation gets heavy, Elena steps outside to let the ladies have their privacy. She is then confronted by Stefan. They start arguing. Jamie comes out and tries to intervene. Stefan gets rough with Jamie and compels him to go inside. Jamie walks off. Elena blasts Stefan, telling him she doesn't think he has a clue about how bad he's gotten. Part of me agrees, until I remember YOU'VE KNOWN FOR MONTHS THAT STEFAN RIPS PEOPLE APART AND PUTS THEM BACK TOGETHER LIKE A JIGSAW PUZZLE, SO IT'S A LITTLE BIZARRE THAT COMPELLING A GUY TO GO IN HIS HOUSE PROMPTS THIS CONDEMNATION, ELENA. Ahem.