Meet Our Staff
Tammy Harbison
Executive Director
Tammy has led Sun and Stars Montessori since 2008 with a deep commitment to nurturing both a love of learning and a foundation for lifelong success in every child. She creates an early childhood environment where each student feels valued, supported, and inspired.
“Love, learning, and community come together to help every child thrive.”
As a former Montessori student herself, Tammy believes that self-directed learning cultivates curiosity, independence, confidence, and a genuine joy in discovery. She also enjoys fostering connections among families, creating fun opportunities for parents to gather and build a strong, supportive community.
Maria Garcia
Lead Montessori Teacher- Suns
Maria has been a cherished member of Sun and Stars Montessori for more than 40 years, bringing a deep commitment to growth and patience to her work with children. Utilizing her AMS training, she thoughtfully prepares classroom environments that reflect each child’s evolving interests, creating opportunities for meaningful challenge and steady growth.
“Helping children grow into compassionate, capable leaders is the most rewarding part of teaching.”
In addition to teaching Spanish, she is especially passionate about guiding children through their “Leadership Year,” the final year before Kindergarten, when they take on meaningful roles and responsibilities within the classroom. During this time, Maria supports each child as they strengthen their social and leadership skills—helping them become ready for their next chapter.
Nelida Jacobo
Lead Montessori Teacher- Stars
Neli has been a valued member of Sun and Stars Montessori for over 20 years, bringing a strong commitment to growth and healthy connections to her work each day. She continues to learn alongside the children, embracing new experiences and staying up to date with research that supports the home-school connection.
“Open communication and strong partnerships with parents are essential to every child’s success.”
She especially enjoys working with two-year-olds, appreciating their curiosity, honesty, bravery, and sense of humor. Neli is dedicated to building meaningful connections with families to support each child’s unique needs and ensure they thrive.
Lucero Guzman
Lead Montessori Teacher – Little Dippers
Raised in St. Helena, Lucero brings a deep appreciation for family, community, and connection to her work at Sun and Stars Montessori. She values the strong relationships she has built with parents, teachers, and children, believing a supportive, family-centered environment is essential for every child’s growth.
“Each developmental milestone is celebrated together, as a family.”
As a teacher in the Little Dippers class, Lucero witnesses many meaningful “firsts” and approaches each day with adaptability, responding thoughtfully to the unique needs of the toddlers in her care. She values the joy and collaboration at Sun and Stars, where children, teachers, and families learn and grow together.
Johanna Muessel
Lead Teacher – Suns
Johanna was born and raised in Finland, where she earned a Bachelor of Arts in Early Childhood Education. She brings a spirit of adventure and a deep respect for truth to her work, inspiring children to explore their world with curiosity, honesty, and confidence.
“Curiosity and shared adventure make every day a learning opportunity.”
Before joining Sun and Stars Montessori, Johanna followed her love of travel and teaching around the globe, working in Cambodia, Japan, Vietnam, Singapore, Finland, and the United States. She is passionate about trying new things alongside the children, encouraging hands-on discovery and thoughtful risk-taking. Cultural connections and shared adventure are to be celebrated.
Teacher - Suns
Alexia brings a natural warmth and ability to connect with children to her teaching at Sun and Stars Montessori. She is pursuing a Bachelor of Arts in Early Childhood Education at SSU, among many other endeavors.
“Respect, kindness, and joy make every classroom a community.”
Alexia fosters social development, creativity, and self-expression, taking the time to truly listen to each child. She is often seen smiling, laughing, dancing, and playfully engaging with students. She deeply values the strong sense of community at Sun and Stars, where teachers, children, and families work together with care, compassion, and mutual support.
Rosaura Alvarez Calderon
Teacher – Stars
Rosaura supports children in learning and practicing Spanish throughout the day, fostering confidence and cultural connection. With a degree in psychology, she nurtures each child’s curiosity and sense of self, creating a thoughtful and engaging environment where children feel supported and families are valued as partners in learning.
“Children thrive when curiosity and family support are at the heart of learning.”
Rosaura brings creativity, adaptability, and a calm presence to Sun and Stars Montessori. Guided by a strong sense of faith—an inner trust that positive outcomes are possible and that experiences unfold as they are meant to be—she approaches changes and actions with confidence and intention.