Lady Eve's Last Con - Rebecca Fraimow

Ruth Johnson and her sister Jules have been small-time hustlers on the interstellar cruise lines for years. But then Jules fell in love with one of their targets, Esteban Mendez-Yuki, sole heir to the family insurance fortune. Esteban seemed to love her too, until she told him who she really was, at which point he fled without a word.
Now Ruth is set on revenge: disguised as provincial debutante Evelyn Ojukwu and set for the swanky satellite New Monte, she's going to make Esteban fall in love with her, then break his heart and take half his fortune. At least, that's the plan. But Ruth hadn't accounted for his older sister, Sol, a brilliant mind in a dashing suit... and much harder to fool.
Sol is hot on Ruth's tail, and as the two women learn each other's tricks, Ruth must decide between going after the money and going after her heart.