Marietta is the Founder and Co-Owner of Red Rock Volleyball Club, overseeing all locations, and also founded Kai Beach Volleyball Club. As one of the most accomplished club coaches in California, she has led teams to Junior Nationals year after year while guiding athletes through the recruiting process to earn opportunities at top collegiate programs such as USC, UCLA, Harvard, Columbia, UC Santa Barbara, Santa Clara, and many more.

Marietta founded Red Rock Volleyball Club in Redwood City, where she coached for over a decade and led all her teams (14s–18s) to Junior Nationals in either the Open or National divisions. Under her leadership, her Red Rock 18-1 teams had numerous accomplishments including Northern California regional titles, top-10 finishes and a bronze medal at USAV Junior Nationals. She has also achieved Open medals at Triple Crown NIT and major qualifiers including Far Westerns and Pacific Northwest.

She later expanded Red Rock to the Walnut Creek/Danville area where she continues to develop a top-performing program. In the 2024–2025 season, her Red Rock 16-1 team won the Northern California Regional Championships and qualified for Junior Nationals. In the 2023–2024 season, her 15-1 team placed 2nd at the Pacific Northwest Qualifier, earning a bid to the Girls' Junior National Championship, and took 3rd at Regionals, achieving a double qualification. The prior year, her 14-1 team finished in the top 5 in Northern California and qualified for Junior Nationals—a notable accomplishment in just the second year of the Danville program. In its inaugural season, her 14-1 team finished in the gold division (top 12) regionally.

Previously, Marietta led the varsity girls' volleyball program at St. Ignatius College Prep in San Francisco from 2016–2018. In her first season, she transformed the team from a national ranking of #447 the previous year to #27, and finished 3rd in the California Open Division State Championships.

Born and raised in Louisville, KY and New Albany, IN, Marietta is the daughter of former professional basketball player Mike Flynn and grew up in a family deeply rooted in athletics—her three older brothers each played Division I basketball. As a junior athlete, she won a Gold Medal at the USA Girls' Junior National Championship (15s) playing for Kentucky Indiana Volleyball Academy (KIVA). At New Albany High School, Marietta excelled as a four-year varsity volleyball player as an outside hitter on a nationally ranked top-50 team. Her senior year, she was named league MVP and received both the Overall Top Female Athlete Award and the Top Scholar-Athlete Award. 

Marietta went on to attend Santa Clara University, where she played libero and graduated magna cum laude with a Bachelor of Science in Accounting and Finance. She is a Certified Public Accountant and a finance leader in the biotech industry, while also running both Red Rock Volleyball Club and Kai Beach Volleyball Club. “Players often express their desire to follow in my footsteps. Seeing their growth over the years—on the court, academically, professionally, and personally—is the most fulfilling aspect of my career. My goal is to remain a source of inspiration for all student-athletes.”

Marietta resides in Danville, where she enjoys quality time with her family, staying active at the gym, showering her two cats with endless love, and supporting her favorite sports teams…Go Warriors!!