Here, we present the raw EEG data from our investigation into the neurophysiological differences in language processing between children with developmental language disorder (DLD) and their typically developing peers. Building on previous findings of prosody perception difficulties and their impact on language development, we aim to describe the Mismatch Responses (MMR) of both groups when perceiving the unique three-way quantity distinction of Estonian prosody. This study is longitudinal with two measurement points. Here, we present the findings from the second measurement and compare them to those from the first. Our methodology involves compreheensive psychometric testing and complete EEG examinations for the DLD group, alongside a passive oddball paradigm with various stimuli. We also explore potential correlations between neurophysiological and behavioral results and investigate the influence of environmental factors.