Rough Daddy by Megan Michaels

Finally home from his last deployment with the Green Berets, Knox Chambers is aiming to settle down and start a family, not look after a feisty eighteen-year-old… until he meets Marli Brown.
When he finds Marli squatting in the run-down bar he plans to fix it up, Knox can’t help wanting to take her under his wing. But can he be the man she’s always needed but never had in her life?