There is only one scene with full frontal nudity. It's in the latter half of the movie when one of the older girls (Bérangère Haubruge, 13) is sitting in a metal tub in the bathroom. She gets out, looking at her reflection in the mirror and as she stands you get a fleeting glance of her completely nude.
Nudity of Anton's two younger sisters Mareike (Juana Hoppe, 4) and Mariechen (Katja Heinrich, 5) being lifted out of the bathtub and standing in the living room after bath.