The opportunity to pursue her dream is why she left.
"I just feel like I have such a calling to special education," said Booker, who plans to get her special education credential in May. "I have always wanted to be a teacher ever since I can remember. It wouldn't be fair to Vanguard to be a college coach and go into teaching for my first two years."
Booker stepped down from the college coaching ranks to take over a high school girls' program. Not just any program, but Corona del Mar, one of the volleyball hotbeds in Southern California.
Since being in charge of her first high school varsity team, Booker has noticed a difference between Vanguard and CdM.
"In college, parents send their kids to college," Booker said. "In high school, parents drop their kids off [at] practice."
How Booker gets her athletes has changed. What has not is how she builds relationships with every player and mentors them.
Fourteen are members of the varsity team. All 14 have made an impression on the new coach.
"They're so driven," Booker said. "They are very driven and want to succeed. Not that Vanguard didn't have that. It's just … they want to be so good."
The group at CdM this season reminds Booker of her former teams. Do not hold it against her that those teams were as a player at Back Bay rival Newport Harbor in the late 1990s. She went by Marissa Cothran back then.
She played on CIF Southern Section Division I-AA and CIF State Division I championship teams. She knows what a championship-caliber team looks like, what it has in its DNA.
She played with the likes of April Ross, Brenda Waterman, Krista Dill, Heather Cullen and Kathy LaVold. They all played roles in helping Newport Harbor win three straight section titles from 1997-99 and Booker said the key to the success on the court was unity.
"Our team was extremely close," said Booker, who graduated in 1999 from Newport Harbor. "A majority of us still talk to each other and are still friends.