Griffin was an amateur astronomer who had always liked to study the heavens since he was small. He was out walking in park one night, taking notes, when he saw a lovely, dark lady strolling around, not interacting with anyone, just enjoying the night. He finally mustered enough courage to go over and talk to her, and after conversing a while he invited her to his home. The mysterious woman spent the night, then left the next day.
Four months later, a newborn baby girl showed up on his front step in Manhattan, New York, a note pinned to her blanket, explaining to Griffin that this girl was his child, and that he must take care of her. The note said her name was Selena Estrella. He decided to take the baby in, and took care of her to the best of his ability.
Even during her early years, from about the time she started elementary school, Selena was shunned, called a "Goth Girl," and a "Freak," by the others, because she was very shy and didn't talk much, and was naturally unsociable. On top of that, she was diagnosed with ADD, and ADHD in fourth grade -- when she was ten -- and dyslexia in the fifth. She noticed she felt better at night, when she could concentrate, which led to many nocturnal outings with her father, who still liked to examine the stars, especially in the company of his young daughter. They would just go out at night, taking note of the sky and pointing out the different constellations, which Selena was extremely good at. She liked to wear black clothing, and she normally didn't talk much, so she didn't have any friends all the way through elementary school. Instead, she spent a lot of time with her father, studying the sky and taking long walks in the moonlight, where she felt stronger and more herself.
When she started middle school at eleven years old, sixth grade, her problems only got worse. She remained as secluded as ever, and quietly moved onto the seventh grade.
By the time she was twelve, she had been expelled from her school for causing trouble she could not explain, though always blamed for. A rather annoying girl had bullied and taunted her, and with Selena's short temper, it didn't take for her long to react. She conjured a rope made of darkness without meaning to, and they wrapped themselves, seemingly of their own accord, around the girl's torso, until the ropes disappeared because of Selena's surprise. Her brain told herself that she had seen ropes made of shadow materialize, but she insisted to herself that she had used a jump rope or something, which is also what the teachers also had to believe. She was expelled because the mean girl's influence on the school.
The second time she was expelled was when her class went on a field trip, and they all ended up in a pitch black planetarium because Selena had accidentally flipped the power switch while searching for her gift shop bag, then the whole circuit blew out because of an electrical storm. The teachers, who were by then looking for any excuse to expel her for the other trouble she caused at a smaller amount, expelled her instantly.
A couple months after Selena's thirteenth birthday, her father married a woman named Chelsea Brown. She was a nice lady, but she did not approve of Selena's choice of black clothes, or how she had no friends. She was always spending time with her dad, and this made her step-mother quite happy, so she left Selena alone, figuring it was an unofficial compromise: spend time with your father, and I won't complain about the attire.
The last time she was kicked out of a school, in eighth grade, a harpy attacked her while she was out in the schoolyard, rather secluded from everyone else. They chased her halfway around the school, causing a lot of commotion and making many students and people rather annoyed. Selena was cornered quickly, and the harpy would have been pecked and clawed her to death if a large group of students and teachers hadn't arrived, coming to gawk and yell at her for causing a ruckus. A mortal girl, who could see through the Mist, screamed and threw her backpack at it, forcing the bird to scatter, giving Selena time to partially compose herself and grab the backpack. She gradually beat them off, and the mortal's presence, plus the unwillingness to get whacked with a backpack anymore, the monster fled, but not without infuriating half the school, not to mention destroy a good part of the school's supply of dodge balls, jump ropes, and balls in general, in Selena's attempts to slow the harpy. Of course, Selena was blamed for all this and was expelled. No one believed her story that it was a "bird lady," and not a loud and vicious pigeon that assaulted her.
When she started going to high school at fourteen years old, she met a boy named Willard Green, who was in ninth grade, short, had acne, and was teased like her. They became good friends, although Selena did not know that this was a satyr. He wasn't sure whether this was a half-blood or not, and decided just to wait it out. They became closer friends, and Chelsea and Griffin were pretty happy about that she finally found a friend. They did most of the normal things middle schoolers do, including Willard introducing Selena to Mythomagic, a card game involving figurines. They all lived in peace for quite a while.
About four months later, just before Selena's fifteenth birthday, two gigantic scorpions attacked while she was walking home from school. Thankfully, Willard was with her, and attacked them with his pipes, playing a nature song, causing their stinger to be turned into flower buds. Selena, however, panicked and grabbed Willard, diving into the darkness of an alley, where she was unknowingly cloaking them in shadow in the dark alleyway. Selena collapsed soon after from the exertion of using her powers so suddenly, after not using them at all before then, and Willard to be left to haul her to Camp without help. Willard was frantically playing his pipes to slow the monsters down, though he himself was becoming more and more tired. Willard had a big head start and ran, dragging an unconscious Selena toward Camp Half-Blood by playing his pipes, causing vines to shoot up and drag her like a dog sled behind him. Thankfully, the giant scorpions were rather slow when scuttling along, and not very dangerous without their stingers. Even so, Willard barely made it behind the barrier before the scorpions could catch them and rip them to shreds, even though they were without weapons. The giant scorpions were killed, and Willard and Selena brought to the infirmary.
Selena woke up four days later, and although very weak, she was still alive; Willard was up and about also. She was a little worried about what her father would say when she explained why she missed her fourteenth birthday, and basically about her disappearance in general, so she contacted her father, telling him she was going to a cool "free camp for special kids," and he did not ask questions, but allowed her to stay. She was claimed by her mother the first night she was sitting by the campfire, and not in the infirmary. She was given her weapon the night she was claimed, she and Willard went searching through the armory, and she felt drawn to a particular sword, so she kept it, calling it Athóryvos, meaning "silent" in Greek.