to remove Simpson as her father, click on the edit tab at the top of her profile. On the right, there are relationships. Click edit father. Then you will have the choice to replace or remove. Click remove. You will go to the bottom of the page. Remove. Scroll down a little more. There is a save button. Make sure you click on that.
On her mother's profile, you can add her second husband. Also, if your parents were married, you can connect them from either of their profiles by editing relationships, etc.