Can't find this book

During the Civil War, a man killed the main girl's brother during a battle. She wanted to avenge her brother, so she decided the break the killer's heart. She attended General Grant's funeral so that she can meet her brother's killer. She slept with the killer, then left him in the middle of the night, which made him mad and sad. When he finally found her on a ship, she pretended that she was forced to marry another man to survive. I believe the other man was her uncle or something. Her name starts when an "R." It might be Rachel or Rochelle. I can't remember. Anyways, she has a Ranch in the West that is called "RR" which are the initials of her name and her brother's name. I think her brother's name is Richard. The main guy's ranch is "R" because he named it after her. Therefore, her cattle are branded with the letters "RR" while his cattle are branded with the letter "R." She stole his cattle by branding them with another "R" so that it will read "RR." She ended up breaking his heart again, even though she was falling in love with him. In the end, she confessed to the guy about the truth. They made up and got back together.
It was a good love story but I read the book a long time ago so I can't remember everything now. Please help me find it. Thanks.