Frederick William I, Duke of MecklenburgSchwerin was the reigning Duke of Mecklenburg in the MecklenburgSchwerin portion of the duchy of Mecklenburg from 1692 until 1713.
A lady named Frederika Wilhelmina was born 1702 in Boitzenburg and died 1748 in Schwerin. In 1719, she married 1719 Hermann Christian von Wolffradt . She was a mistress of Duke Karl Leopold of Mecklenburg. Whether she was an illegitimate daughter of Frederick William is a point of controversy in the historical literature.
Source: Wikipedia