Messalina and Coriolanus were married when the ink wasn't even dry on the divorce papers, and their marriage lasted almost five years. That time saw Messalina give birth to a daughter Corralina (Alma Coin), and Snow beginning to lose interest in her. Unlike Julia who put her hands up and surrendered, Messalina fought Coriolanus every step of the process. Violent tantrums, throwing divorce requests in the fire, you name it.
Finally Snow decided that it was time to get rid of her for good. His mother was more than happy to assist in bringing false treason charges against Messalina. She was tried, found guilty, and executed. This happened three years after giving birth to her. She died in 30 ADD.