Although children are particularly vulnerable to accidents while crossing a street, knowledge about their specific perceptual and behavioral responses to crosswalk design and conditions is limited. By employing simulated virtual reality (VR) experiments, this study investigated how the environment of an unsignalized T-junction in a school zone influenced the perceived safety, crossing behaviors, and visual attention of 178 participants, consisting of younger (aged 8-10) and older children (aged 11-12) and their parents. Key findings from cross-classified multilevel, trajectory, and counterfactual analyses using Reproduced Virtual Experiment Data (CARVED) techniques for viewed scene comparisons are as follows. First, despite their physical and cognitive limitations, children-particularly younger ones-exhibited fewer attentive behaviors on sidewalks and roadways, along with a higher informal crossing ratio than parents. Second, responses to environmental conditions varied by developmental stage. While older children and parents generally responded to hazardous conditions with increased caution, younger children exhibited minimal behavioral adjustments. For example, parents perceived environments with parked cars as less safe and demonstrated more attentive and preventive behaviors on roadways. In contrast, younger children, despite having their line of sight obstructed, failed to recognize these hazards and did not adopt compensatory strategies, reinforcing their vulnerability. Similarly, only older children and parents perceived decorative crosswalk patterns as less safe than traditional ones. Third, while traditional crosswalks facilitated orthogonal crossings and provided clearer guidance for safer movements, decorative patterns often encouraged diagonal and dispersed crossings, resulting in a higher jaywalking ratio. Lastly, speed limits showed no significant influence on perceived safety or crossing behaviors. These findings highlight the critical influence of developmental stages on safety perceptions and behaviors, emphasizing the need to reassess crosswalk designs and address visibility challenges caused by illegal on-street parking to enhance child pedestrian safety.