Laura Lippman introduced Heloise Lewis in Scratch a Woman, a work too long to be a short story and too short to be a novella, published in Hardly Knew Her. Given an entire novel, she's less of a cypher and a much more sympathetic character than I expected from the Suburban Madam set-up.
We first see Heloise in her other guise, perfect suburban mother, getting coffee in Starbucks. As she coolly and logically dresses down two patrons sneering at the story of a murdered suburban madam, she reflects on how shocked those customers would be to know that the perfectly calm and coiffed redhead standing next to them is also a prostitute who both sees personal clients and runs an escort service under the guise of a lobbying firm, the Women's Full Employment Network. No one knows, or suspects, that the slightly standoffish widow with the perfect life is not as she appears.
Lippman could have used the Suburban Madam Murder as an impetus for Heloise to get out of her business, but she's a more subtle writer. The crime does nag at Heloise, but it's not her greatest problem. One of her former employees claims to have contracted HIV while working for WFEN, her contact (and occasional protector) on the police force is about to retire, and her accountant *may* suspect that there's something wrong. But how can she get out of the business when her imprisoned former pimp (and her son's father) takes half the profits and will have her killed if she tries to leave? Lippman combines a tightly constructed mystery (although one with two or three more coincidences than I'd like, and a denouement that's just a bit too pat) with flashbacks which show how an emotionally and physically abused teenager named Helen became a prostitute, an informant, and finally the woman she appeared to be.