Karoline (born 25 January 1860) appears to be around 15. Auguste Victoria (born 22 October 1858) is an older, but still teenage, girl. That would date this to ca. 1875, but the full silhouette is guesswork. This could date to as late as ca. 1878 if the skirt is columnar with almost no bustle. 1875 skirts often looked triangular if seen from the side.
They were the daughters of Princess Adelheid of Hohenlohe-Langenburg.