She was always taller than Miorine, from the beginning of the series (actually, most characters were probably taller than Miorine when you think about it lol). I didn't notice if she got even taller by the end, though its definitely possible she did.
I think this artist's style is just different from the show, since Miorine also doesn't have the super thin physique of the anime and they haven't really drawn muscles on Suletta.