The Larsen family were a long line of Norwegian pure-bloods, one of the typical anti-muggle pro-purity lines who looked down on those lacking in magic. They had a son, Kristoffer, who happened to be a squib. So, at the age of ten, when they'd lost all hope of him showing magical ability, they sent him off to an orphanage and told everyone outside the family he'd caught dragon pox and perished.
In reality, the boy thrived, adopted by a well-to-do couple in England at age twelve - one of whom was a squib herself - and receiving high-calibre education in Eton and Oxford. Eventually he met the very pretty, very magically adept Viola Macmillan, a recent Hufflepuff alumna.
They married the next year, a few months before Viola inherited ownership of her parents' popular sweetshop, and eventually went on to have three children. The second eldest, Astrid Lillian Larsen, was born only minutes after her twin brother Kell. He was always the more preferred of the two, but she was a daddy's girl through and through. While Kell was always the one being focused on, she was always a background person
Her first sign of magic came when she was eight in her parent's sweet shop. Nowadays, Astrid hates sweets, but then, she could't get enough of it. Her parents had banned her from eating chocolate, and she had snuck some. When she was about to get caught, the candy suddenly disappeared - She could later find it under her bed. She was caught the next day. That was also the week she was signed up for kid gymnastics.
Her parents were always obsessed with keeping their children healthy. While they were allowed as many sweets as they wanted, to their parent's discretion, they were not to eat enough to negatively affect them. Eventually, with candy being related to working out, Astrid stopped eating candy all together. She likes sports, now, but she hates candy. they leave a disgusting flavor in her mouth.
When it was time, the twins were sent to Durmstrang, for the chance to connect with their heritage, or whatever. Astrid would have preferred Beauxbatons if anything. Her time at Durmstrang was anything but pleasant. People teased her for being a Jock, and not all that good with school work. They either did that, or never paid mind to her, which only annoyed her more than being picked on.
It was around 14 when she started to feel the affects of the bullying, and the negligence from her parents. That was when she having her first few episodes of depression - Purely, it was her finding the inability to do anything she used to do interesting. She could barely find the motivation to get out of bed. Astrid had started missing class and her grades plummeted. Then she'd get a poush to do something productive, and slowly everything would start up again. Slowly. Then they'd fall off another cliff. It was a vicious cycle.
Now that a new year is starting, the Norwegian teens find their way to Hogwarts, where they continue their education... And maybe where Astrid can get a fresh start.