Aurora Bullwarke

Backstory

She is a Squib-born witch. Her mother had just enough magical talent to be accepted into Hogwarts for three years but had to drop out after failing the fourth. Her father never made the cut and works in the muggle world. Her mother has an maintenance role in the Ministry.
She would say she has had the best of both worlds, the school life and technologies of the Muggle world and the magical candies and entertainment of the Magical one. However due to the nature of it, her and her family never fully fitted in either - treated as lower class citizens or as weird shut-ins.
Even though she knew of magic from day one - it was never a viable option. It was just assumed from her family that she wouldn't show enough ability to classify as a witch. They were half right - leading up to her 11th birthday there hadn't been any magical outburst or weird occurrence. She was saddened, she wanted to be apart of the magical going ons in the school of wizardry. However on the night of her 11th her father and her were walking back from Diagon Alley (Birthday treat) when they were set upon by a muggle crook. The would-be robber tried to shoot her dad when he was calmly taking out his wallet (it was spelled to return in a day anyway) and Aurora somehow constructed a fully formed and incredibly strong shield spell out of sheer reaction.
Her letter arrived the next day.