Helene Jemima Reynolds was born to two pure-blooded Slytherin graduates who married as soon as they left school. Instead of adhering to the traditional purist ideals of their respective families, they saw an opportunity in the muggle world and took it. Helene's father founded a series of luxury resorts and other successful business endeavours which quickly propelled them to wealth, while her mother set about making herself a socialite.
Helene was born two years after the couple had made their first big money, meant to be a fix-it in her parents' rapidly failing marriage. It worked, for most of her life, too, but mostly just because "we couldn't do that to our daughter." She was an excuse to stay in a marriage whose end would spell trouble for her mother, thanks to a prenuptial agreement insisted upon by her paternal grandparents.
Her father working pretty much 24/7, her mother more interested in her friends than her daughter, Helene was raised almost entirely by the family house elves, who were always sure to stay well out of the way of any muggle visitors. In the rare moments when her mother was actually feeling motherly, she'd send the house elves elsewhere, spend twenty minutes with Helene, get bored and leave again. Naturally, this did wonders for Helene's self esteem.
Age eleven, Helene's parents chose to send her to Beauxbatons, which she attended with a host of other rich, beautiful social butterflies. As she grew older, she became more and more painfully aware of her mother's rebuffs, of her friends' beauty and apparent ease of mind, and became more and more insecure about herself. Eventually she developed bulimia in her third year, and was hospitalised twice for it in her fourth year. As soon as the year was over, her parents decided to transfer her to Hogwarts for a "fresh start".
By the end of her sixth year, after extensive treatment, Helene had made a full recovery in the eyes of her parents, and had even finished OWLs the year before with fairly good grades. She'd always have private problems with self esteem, but on the outside she was the picture of confidence. At the end of sixth year, she asked her father to allow her to drop out and travel, and was sent on her way with a supply of money and his approval.
A few days later, Helene had rented an apartment in London, gotten a job as an exotic dancer and cut off contact with her mother - not with her father, but he didn't really care about her antics. She made sure everyone she knew knew about it, and even people she didn't know. It even made its way into a few of the more obscure tabloids. She wrecked her reputation, her parents' reputation, scandalised their entire social circle, and then waltzed back into her father's house a year later.
When she got home, she was informed that while she was off "making a spectacle" of herself, her parents' marriage had broken down. Well, her mother had caught one of her father's mistresses leaving and stormed out, and her father had filed the divorce the next morning. Thanks to their prenuptial agreement, her mother was left with very little compared to her father, although, honestly, Helene can't bring herself to pity her. Her father had pretty much shrugged at the divorce and gotten back to his money-making, and he treated his daughter's return with another shrug and welcomed her back into his good graces.
Now, Helene is still estranged from her mother, but living it up anyway. She couldn't honestly care less.