In 1921, Mackaye met Ray Raymond while performing in "Blue Eyes". Raymond dumped his wife, they married, and acted in vaudeville and on Broadway.

In the late 1920’s, they headed to LA with their 4-year-old daughter, Valerie to cash in on the Talkies.

The Raymonds were part of a fast-moving, heavy-drinking crowd that included actor Paul Kelly. Soon, Kelly and Mackaye developed a habit of sneaking off together until dawn. Raymond warned Kelly to stay away from his wife. But Kelly showered Mackaye with love notes and finally declared his love for Mackaye to Raymond.

On April 16, 1927, a drunk Kelly confronted a drunk Raymond in front of the Raymonds’ maid and daughter. According to the maid, Raymond was no match for Kelly who bashed Raymond's head against a wall until he fell unconscious. Mackaye arrived home to tuck her groggy husband into bed. The next morning, Mackaye called a friend, Dr. Walter Sullivan, who sat at Raymond's bed while she visited Kelly. Raymond lingered for two days then succumbed to a brain hemorrhage. Mackaye tried to convince police that Raymond had died of natural causes. But the maid told the truth. Kelly was charged with first-degree murder, Mackaye with felony coverup.

The trial was a national spectacle. Mackaye denied the affair, but the actor's houseboy confirmed their trysts and the police found a stack of Kelly's love letters found tucked in her mattress. Kelly admitted his love and tried to portray the fight as a duel, not a murder. But the jury handed down a manslaughter conviction. Kelly got one to 10 years, Mackaye one to three for the coverup. She served less than 10 months, Kelly just over two years.

In 1931, they got married and were back on Broadway. Then they returned to California, where they raised Valerie Raymond as Mimi Kelly, who would later have her own modest Broadway career.

Mackaye wrote a play, "Women in Prison," based on her own experiences, that became a 1933 film, "Ladies They Talk About," with Barbara Stanwyck.

She died in 1940, at age 40, when she rolled her car while driving home one night.