Understanding speech in noisy environments, such as classrooms, is a challenge for children. When a spatial separation is introduced between the target and masker, as compared to when both are co-located, children demonstrate intelligibility improvement of the target speech. Such intelligibility improvement is known as spatial release from masking (SRM). In most reverberant environments, binaural cues associated with the spatial separation are distorted; the extent to which such distortion will affect children's SRM is unknown. Two virtual acoustic environments with reverberation times between 0.4 s and 1.1 s were compared. SRM was measured using a spatial separation with symmetrically displaced maskers to maximize access to binaural cues. The role of informational masking in modulating SRM was investigated through voice similarity between the target and masker. Results showed that, contradictory to previous developmental findings on free-field SRM, children's SRM in reverberation has not yet reached maturity in the 7-12 years age range. When reducing reverberation, an SRM improvement was seen in adults but not in children. Our findings suggest that, even though school-age children have access to binaural cues that are distorted in reverberation, they demonstrate immature use of such cues for speech-in-noise perception, even in mild reverberation.