In the Garden of Spite by Camilla Bruce

They whisper about her in Chicago. Men come to her with their hopes, their dreams–their fortunes. But no one sees them leave. No one sees them at all after they come to call on the Widow of La Porte. The good people of Indiana may have their suspicions, but if those fools knew what she’d given up, what was taken from her, how she’d suffered, surely they’d understand. Belle Gunness learned a long time ago that a woman has to make her own way in this world. That’s all it is. A bloody means to an end. A glorious enterprise meant to raise her from the bleak, colorless drudgery of her childhood to the life she deserves. After all, vermin always survive.