Never Trust a Snake
"Us snakes are smarter than the lions; we don't form silly bonds with those who will one day come along and stab us in the back."
The moment the raggedy hat touched her head it thought to play a joke, insolently suggesting she join the lions. This was considered a moment longer than necessary, as Sirius had taken those colors a year prior, but no more. Born to a pureblood family, raied alongside the Blacks, and Reg already sorted made the decision an easy one. Her relationship with Sirius was never quite the same.
Murder and Mayhem � Secrets Unfold
�We regret to inform you of the passing of Mr. Thaddeus Davis. He served us well.� - April �74
The death of the patriarch while working for the Ministry caused her mother, who had already been mentally unstable, to completely lose her grip on reality; she was hospitalized in St. Mungos, a few weeks later and moved to a muggle psychiatric hospital once the healer's concluded that no magical intervention could be enacted. Sirius, Regulus and Mr. and Mrs. Black are the only ones privy to this shameful secret.
With no parents, and hardly any funds, the Dark Lord provided the sums necessary for her mother's care, while the Black family, already used to having Lucy during the summer, invited her to live with them.
It was only several years later that she discovered that her father had been brutally lynched by three co-workers, their identities unknown. An obsession with vengeance ensues; seeking to annihilate a corrupt system, her decision is made to join the force that sought to bring the Ministry down, the Death Eater; this, very much in spite of her utter disagreement with the Dark Lord's view on muggles.
Swallow like a Good Girl
Always a valued player for the Slytherin team, Lucy joins the little known "Swooping Swallows�; the first female to ever wear the team colors; their captain's choice to have them reside in the same household and her teammates' rowdy nature, often makes headlines and many scandals were appear in the papers (see Rita Skeeter�s varied articles on the topic). So, an obscure team gains notoriety.
A Very Bad Girl
�Sticks and stones may break my bones but chains and whips excite me.�
Lucy knew how to savor the sensation of the slow ebb of human blood onto her fingers; she could even enjoy them, when there was a purpose. She rejoiced in the torture of Ministry officials, getting them closer to her goal, replacing the regime.
Reformation
The pointless murder and torture of muggles was not something she approved of. Despite her upbringing, she never believed in blood statuses, this made it difficult for her to remain among the Death Eaters. One in particular enjoyed using imperio, making her perform heinous acts, causing her to emerge in the aftermath. The murder of children, their twisted expressionless faces, were the final blow. She deserted, joining the order few weeks before the Dark Lord's demise.