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Meet Our Team

Shawn V Giammattei

Shawn V. Giammattei, PhD

Dr. Shawn Giammattei (he/him) is the founder of Quest Family Therapy and is a licensed family psychologist in Northern California, who specializes in couple and family therapy with a focus on the treatment of gender incongruence in children, adolescents and adults, as well as lesbian, gay, bisexual and transgender couple and family issues.

Lisa Richards

Dr. Lisa Richards, PsyD.

Dr. Lisa Richards (she/her) received her doctorate in clinical psychology, forensic track, from California School of Professional Psychology at Alliant International University. Dr. Richards is a member of the LGBTQ+ community and is also a certified LGBT-informed therapist by The Rockway Institute in San Francisco.

Villa Barrett

"Little" M Vila-Barrett, LMFT

Little (they/them) is a transgender rights advocate, transracial Indigenous adoptee from Colombia, a queer mixed-race person, community activist, and mental health advocate. Little has been working with young people in various levels of programming and community-based mental health roles for over 20 years.

Kimberly Liang

Kimberly Liang, AMFT

Kimberly (she/they/ze/zir) received her master’s degree in Counseling Psychology from The Wright Institute in Berkeley, CA. She is a Registered Associate Marriage and Family Therapist supervised by Shawn V. Giammattei, PhD. while working towards licensure. Prior to graduating, she primarily worked with the mandated adolescent and young adult population for concerns around drug and alcohol use and anger management. 

Caitlin Casey

Caitlin Casey, ASW

Caitlin (she/her) received her master’s degree in Social Work from Boise State University and is a Registered Associate Social Worker supervised by Jill Rees, PhD. while working towards licensure. Caitlin’s clinical approach is rooted in social justice and equity, and supporting the LBGTQ+ community. Caitlin’s previous experience working with individuals and families in equine training taught her the value of compassionate individualized approaches, and she carries that lesson into her clinical work.
Petra Janopaul

Petra Janopaul, AMFT & APCC

Petra (she/her) graduated with a Masters of Art in Counseling Psychology from the Wright Institute (Berkeley, CA). She is a Registered Associate Marriage and Family Therapist and a Registered Associate Professional Clinical Counselor, supervised by Shawn V. Giammattei, PhD.

Jill Rees

Jill Rees, PhD

Jill (all pronouns) is a licensed psychologist who has worked with Sonoma County teens, adults, partners, and families for over 20 years. With her collaborative and playful approach, Jill supports people to live more authentic lives. She loves to help people find their way to the change they are seeking, whether it is improving their mood, deepening their connection with themselves and loved ones, or finding and expressing their authentic selves.

Kate Threlfall

Kate Threlfall, PhD

Dr. Kate Threlfall is a systemic therapist who supports client-led changes with a collaborative and integrative approach: blending evidence-based treatments (such as CBT, DBT, ACT, and EMDR), utilizing a narrative lens that is deeply grounded in a relational framework. Kate is a licensed psychologist supervised by Jill Rees, PhD. while working towards California licensure. Kate works with individuals, families, and their systems in a solution focused and strengths-based way. As a compassionate clinician providing gender affirming care is paramount. 


Kristian Gambardella, ASW

Kristian Gambardella (he/him) is a queer transgender neurodiverse mental health provider and advocate. In working with youth and families, Kristian takes an individualized and collaborative approach, utilizing a gender and neurodiversity affirming, strengths-based, trauma-informed and social justice framework.

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