Significant research has focused on caregiver-child interaction in children's museums, but little is known about what caregivers might be observing or perceiving about their children's learning. This study was conducted by the Children's Museums Research Network, and examines what caregivers observe about their children's learning during a visit to the children's museum. Data were collected through online questionnaires (N = 223) and follow-up phone interviews (N = 20) with caregivers recruited from eight children's museums across the U.S. Results show that caregivers could identify numerous things they discovered about their child(ren) in the museum, including their interests, social skills, thinking/problem-solving skills, and emotional regulation. What contributed most to these discoveries was opportunities to watch their children play and interact with others, and to play with unique materials and activities that they don't have access to at home. Signage and floor staff were seen as minimally important. These findings have implications for exhibit design and staff facilitation in children's museums.