Carmelita Williams faces a second-degree murder charge.
She told authorities that her boyfriend had physically and verbally assaulted her last week in Whippoorwill. According to court documents, the boyfriend blocked the door of a hogan, gave Williams a pistol and told her she couldn't leave unless she shot him.
Williams says her boyfriend pointed the pistol at himself while she held it in her left hand. She then fired a round into his chest, holding her son in the other arm.
Williams told authorities she tried to call 911 but did not have cellphone service, and her relatives' phones didn't work either.
Her attorney did not immediately return a message left Wednesday.