Her mother had never been mothered so was clueless about nurturing another human being.
Her husband wouldn't let her become self-sufficient.
Just about everyone else in her adult life hung around her for the goodies.
The only disinterested third party, her grandmother, died when Amy Winehouse was just becoming known. That left her over-the-top talent in the hands of the vultures.
That essentially is what the 2015 documentary "Amy" captures. As a young girl she told her parents that she was bulimic. Neither picked up on the red flag. Young girls with attentive parents didn't need to do that. They were being guided to develop a strong sense of a self.
The meme of the documentary is that Winehouse needed caring attention. And never got it. Therefore all those boundaries which eventually come together as a self never had a chance to sprout and try themselves out.
Eventually to the food disorder she added alcoholism and drug addiction. Her heart finally gave out and she was found dead. Even her music, in the final days, couldn't save her from her own neediness.