West of Heaven — Barbara Scott

Marcella McGovern arrives in Onion Creek, Texas for the reading of the will of her unknown benefactress. Accompanied by the attorney who managed her education but kept the secret of her parenthood, she soon discovers more shocks thank her prim upbringing has prepared her to face.
The late proprietress of the local house of ill repute, Miss Sophie Castleman, and Clint Harte, wealthy cattle baron of the Heart O' Gold Ranch, were murdered in each others arms.
The will names Marcella as their secret daughter and the inheritor of Sophie's bawdy house and all Harte's marketable cattle. Complicating the inheritance is Lucky Desloge, Sophie's disreputable but all too-tempting majordomo, a prime suspect in the murders, and all Sophie's working girls who are in hiding in her boarded-up house.
Then Clint Harte's angry widow issues Marcella an ultimatum, get the cattle off the Heart O' Gold or pay the price.