Models and measurements of subglottal resonances are generally made from adult data, but there are several applications in which it would be useful to know about subglottal resonances in children. We therefore conducted an analysis of both new and old recordings of children's subglottal acoustics in order 1) to produce a fuller picture of the variability of children's subglottal resonances, and 2) to confirm that existing models of subglottal acoustics can be reasonably applied to children. We also tested the effectiveness of recent algorithms for estimating children's subglottal resonances from speech formants and the fundamental frequency, which were originally formulated based on adult data. It was found that these algorithms are effective for children at least 150cm tall.