Deep in the Heart Series by Mae Nunn, Gwen Ford Faulkenberry

She's everything he didn't want...and exactly what he needsMcCarthy Temple, the last unmarried Temple brother, was happy with his safe, predictable world. He had his family, his accounting business and his numbers. He didn't need love. He already had it all...except an assistant. Jacqueline Aimes was the least likely candidate. She was overqualified, gorgeous and only staying in Kilgore long enough to sell her parents' land... moreShe's everything he didn't want...and exactly what he needsMcCarthy Temple, the last unmarried Temple brother, was happy with his safe, predictable world. He had his family, his accounting business and his numbers. He didn't need love. He already had it all...except an assistant. Jacqueline Aimes was the least likely candidate. She was overqualified, gorgeous and only staying in Kilgore long enough to sell her parents' land.But as Jacqueline starts to permeate every aspect of his life, Mac finds it harder and harder to imagine life without her. Jacqueline's passion is her work for children in international war zones, though, not small-town living. So Mac has to find a Texas-size miracle to get her to stay... less