Charlotte von Bechtolsheim from Schloss Mainsondheim by Ferdinand von Rayski, 1839
Philipp Freiherr von Bechtolsheim must have been the girl’s father, see link here, and this the girl’s mother, Caroline Freifrau von Bechtolsheim with her son Moritz, also painted by Ferdinand von Rayski:
And other portraits of the girl’s mother, by the same painter.
source: WikiCommons, Mainfränkisches Museum Würzburg