A native Texan, Mamie attended the Paseo Academy of the Arts in Kansas City, Missouri, before graduating from the American Musical and Dramatic Academy in New York City.

​On Broadway, Mamie most recently returned to the cast of School of Rock on Broadway, this time in the role of Rosalie. She previously starred as Grizabella in the Broadway revival of Andrew Lloyd Webber's iconic musical CATS. Her other Broadway and National Tour credits include: School of Rock (Patty) (cast album), Wicked (Elphaba), 9 To 5 The Musical (as Judy Bernly, the role created by Jane Fonda in the iconic film), the Tony-Nominated revival of Ragtime, 5-time Tony-Winner The Drowsy Chaperone, Legally Blonde- the Musical, and Roundabout Theatre’s acclaimed revivals of On The 20th Century (Agnes) (cast album) and 110 In the Shade (cast album). Off-Broadway credits include Pump Boys and Dinettes (Prudie), part of the Encores! Off-Center series; See Rock City and Other Destinations (Dodi), presented by the Transport Group (cast album out now). Other notable credits include roles at The Goodspeed Opera House, Pittsburgh Civic Light Opera, The Muny, The Macau International Music Festival in Macau, China; and many more. Her film and television credits include The Blacklist (NBC), A Stand Up Guy (Orchard), and State of Affairs (NBC). Mamie resides in NYC with her husband, Johnathan, and pup, Cookie.