Maybe it's because I never paid attention to that specific part, but I really just noticed that Doremy wears a turtleneck.
Though, looking at her portrait in LoLK... that is supposed to be a turtleneck? Actually, now that I look closer – kinda feels like the AoCF one is an entirely different outfit. Her artwork from SCoOW seems closer to the original. For one, that is definitely an apron and not her midriff.