Nugent married actor Nick Adams in 1959, after they dated for a short time. She appeared in a guest role for his television series The Rebel that year. They had two children together, Allyson Lee Adams and Jeb Stuart Adams.

In a 1961 interview Adams said, “Carol is my good-luck charm. My first real success, the turn of the tide, came right after I fell in love with her. Then I formed my own production company and we sold The Rebel.” However, in the same interview Nugent said, “Let’s not overdo the sweetness and light. Naturally, Nick and I had our problems at the start”. Gossip columnist Rona Barrett later wrote that Nugent “was one of the most refreshing wives in the entire community.”

In 1965, seemingly without warning, during a promotional television appearance on The Les Crane Show, Adams announced he was leaving her. This began a very public period of bitter separations and temporary reconciliations which lasted until his death in 1968. Nugent filed for divorce and custody of the children went back and forth between her and Adams but she was listed as his spouse on the death certificate and when he died she was living with their two children only a few blocks from his house in Beverly Hills.

In 2002 Nugent renewed her acquaintance with John G. Stephens who had been production manager on the 1960s television series My Three Sons. Her father Carl had been property master for the show. Stephens’ wife, actress Joan Vohs (1927–2001), had recently died from heart failure. Stephens and Nugent married in 2002.