Annabeth's father, Frederick Chase, met Athena, the goddess of wisdom, battle, and handicrafts, while he was studying history at Harvard. Athena helped him get through his studies and, consequently, they fell in love. Shortly after, in 1996, as a gift to Frederick, Athena sent him Annabeth. She appeared on Frederick's doorstep in a golden cradle carried down from Olympus by Zephyros, the west wind. She was considered a "brain child" like all other children of Athena. However, her father asked Athena to take Annabeth to Olympus and raise her there, as he didn't see Annabeth as a gift the way Athena did. Athena refused and told him that heroes were supposed to be raised by their mortal parents and not their godly ones. In the end, he had no choice but to take her in and care for her as well as he could.
When Annabeth was 5, her father got remarried. He and his new wife had 2 more kids together, Annabeth's half brothers. Because Annabeth was a demigod, her family was constantly being attacked by monsters, causing constant fighting between Annabeth and her parents, as they felt that she was always putting them in danger. When she was little, she used to be attacked, bitten and covered in cobwebs by spiders at night, and she would scream for her father but her step-mom thought she was making it up and refused to call her father because whenever her step-mom came into the room, the spiders would hide away and by the time she got dressed each morning, the bites and cobwebs faded. Being a child of Athena, she had a deep phobia of spiders. As a result, Annabeth felt that her step-mom thought that she was a freak, so she ran away from home at age 7 because she believed that she was not wanted by her family members.
She then fought monsters with the guidance of her mother for a few months, using only a mortal hammer. Annabeth was later found by a son of Hermes, Luke Castellan, and a daughter of Zeus, Thalia Grace. When they found her she was hiding under a sheet of corrugated iron. The 7 year old blonde demigod then tried to attack them with a hammer, but Luke grabbed her wrist and knocked it out of her hand. After being able to befriend her, Luke gave her a celestial bronze knife and said that only a clever warrior could use knives like this one. They traveled all around the States and Canada. At once point when they were in Quebec City, Annabeth came across a little girl with black hair, who couldn't have been more that 5 or 6, hiding in an alley way. The girl was covered in bruises, cuts, scars... some looking self inflicted. Annabeth, despite constant protests from Thalia and Luke, let the little girl tag along with them. She felt a stong urge to protect the black haired girl, feeling some sort of deep rooted connection. Later on, she would find out that this little girl was one of her family members on her mortal father's side. Her little cousin Jordan.
Jordan and the 3 demigods parted ways a couple months after, when the demigods were brought to camp by Grover Underwood, a satyr. She never wanted to go back home and considers Camp Half-Blood her home since she has lived there for most of her life, starting from seven years old. Therefore, she is one of the youngest to ever join Camp Half-Blood.
Annabeth has lived at CHB most of her life, until she was on a quest at the age of 12. Herself and 2 others were in St. Louis, Missouri when she came across someone she hadn't seen since she was a little girl: her cousin, Josh. They spent some time talking, before Annabeth promised that she could come live with him in Vancouver as soon as the quest was finished. She kept that promise, except she still returns to Camp each summer.
Her life couldn't be any better. She has a family that loves her, she doesn't get attacked by monsters (as much), and she has a loving boyfriend. I guess what they say is true: things do get better.