This study used person-centered approaches to examine whether educator beliefs and practices transformed as a result of a randomized coaching intervention focused on the quality of teacher-child interactions. It also considers whether educators' beliefs and practices at the end of the intervention were in turn jointly associated with children's development. Latent profile analysis with a sample of 281 preschool educators working primarily in public school prekindergarten and Head Start programs across nine U.S. cities revealed three profiles of educators with distinct patterns of beliefs and practices: Average, Strong, and Mixed. Random assignment to coaching increased the likelihood that educators belonged to a profile defined by strong beliefs and practices at the end of the intervention. Latent transition analysis suggested that this positive effect was concentrated among a small proportion of educators who either built or maintained strong beliefs and practices. Few differences were found in children's language, literacy, and executive function skills based on educator profiles at the end of the intervention. Implications of this work for educational leaders designing and offering individualized supports for classroom educators are discussed. (author abstract)