Daughter of the southern Unovan "Black Family" mafia, a group of only Dark Type Pokemon inhabiting and ruling over the entirety of the lower half of the region, she's been in the lap of luxury since childhood - after being taken in by her father from the hands of her abusive mother. Being the daughter of the mafia head had it's perks and its downsides, mostly during Bonnie's adolescence when she was being persistently watched by her father's (at the time) best hitman and bodyguard Han, who made it his sole purpose to embarrass her at any given chance to calm her rebellious teen phase. Spoilers, it mostly worked.
Through Han however she picked up a few talents on her own, like learning how to make her own hand crafted, luxurious fur coats, her first one- a Ninetales, being her favorite to this day. It gave her her very first taste of hunting on her own without someone doing the work for her, and began her borderline sadistic tendencies, and her thirst for power. She loved being in control, watching others perish by her own hands and being the one to give orders. She worked her way into her father's good graces after that, slowly gaining his favor and being given more and more freedom and the ability to call shots in the family to an extent. She quickly learned that her father was very comfortable owning only the southern half of the region, upsetting the young Donna to be, and bringing her to slowly work on her own plan of action once her father passed down the torch.
As she grew up she began recruiting her own men, beginning with the rowdy street punk Claudio, who she found great potential in, cleaning him up and protecting his family, indebting him to her with the gift of a prosthetic for his youngest sister, and making him work off the debt with the task of protecting her life and following every one of her orders to a fault, and very swiftly proving her hunch right and proving himself to be a very valuable asset to her, along with her juvenile attraction to the "bad boy with a heart of gold" visage he carried with him bringing her to keep him close, leading to her marrying him a few years later (Much to her father's dismay).
