No matter how you enhanced her looks, currently you couldn’t view Luise as nothing else but a 10-years old. Although you couldn’t deny the potential once she grew up a bit.
Furthermore it was certainly possible that Wendelin in reality liked little girlish women too.
“(To tell you the truth, there is a fixed number of such nobles too …)” (Burkhart)
Such things like the favorite concubine being a small girl, I heard there were many nobles desiring them.