Shadows on the Mirror by Frances Fyfield
Sarah Fortune is bored to death - but few know, and less would guess, how the beautiful and successful redheaded solicitor escapes the stultifying tedium of her career. Since the death of her unfaithful husband, Sarah has found a practical way of transforming the lives of lonely men that also suits her warm and defiant nature.
Kind, witty and obese lawyer Malcolm Cook is the first to benefit from Sarah's generosity - he shrugs off years of weight and loneliness. But then she meets Charles Tysall, an important client of the firm, whose charisma and enormous wealth conceal an implacable will and a misogynist's mad obsession.