CRISTINA A. DE LEÓN, Graduate in Clinical Psychology from the Technical and Higher Education Center of Tijuana, Mexico, Master in Pedagogy from the State University of Pedagogical Studies and Master in Education from Loyola University in Maryland. She received her AMI diploma in Early Childhood Education and in Elementary Education from the Montessori Institute of San Diego. She has over 25 years of experience working with children in both Montessori and non-Montessori environments in Mexico and San Diego, California. She is a Casa de Niños AMI Trainer and Examiner. She has taught Guiding courses in the United States, Argentina, Costa Rica, Taiwan and Spain and is currently part of the Montessori Stoppani Trainers team, Fundación Argentina María Montessori and the Montessori Institute of San Diego.