Beach House Women's Shoreline Shells Empower Underwire Crop Top

I am 5'8, 135 lbs, with a 34E bust and ordered multiple sizes since 'dress size' sizing makes no sense for swim tops. I kept the size 10, as the size 8 had cups that were too small (maybe a C bust?); the item has underwire and a thin cup lining, but no boning on the sides. It is cute, but I am giving it 4 stars because of the ambiguity of having to order multiple tops and pay return fees. I am normally a 'size 6' in dresses, so this sizing, again, is extremely difficult to parse.