Sybille was born on August 28, 2024 to Veronica Belfry - one of the daughters of a very wealthy pureblood supremacist - and Adrien Macmillan - a young wizard that stole Veronica's heart. Sybille Alayna Belfrey is the youngest of three and definitely the quietest - literally. She used to be a babbler until she was in kindergarten. You see, strange things would often happen around the young girl, things that couldn't be explained. She was often bullied by the younger kids which caused her to slowly and surely become quieter and quieter until she stopped talking all together.
Before you say anything, people cope with bullying in different ways. Some people just deal with it, others face it head on. Sybille, however, coped by adopting the belief that she should only speak if what she has to say is important - which is almost never. I say 'almost' because she did speak once when she turned eight years old. It was when her first sign of magic occurred.
It was a very small thing. Something so trivial it would've not even mattered much to another child her age, however for her it did. She found a little red and gold leaf on one of the higher branches in a tree. She wanted this leaf so badly - it was beautiful! - when suddenly, it detached itself from it's twig and floated right into her outstretched hand. So was so happy about this little thing that she immediately went and raced to her mother and excitedly told her everything that happened (while waving the leaf in her mother's face naturally).
When she learned everything she could about Hogwarts, she was immediately overcome with a mixture of overwhelming excitement and dread. What if nobody liked her? What if she was the odd one out again? All she could do was wait and find out. Besides, she can always spend her free time outside...