Friederike's father was the head of the ducal house of Schleswig-Holstein-Sonderburg-Beck, a junior male branch of the House of Oldenburg which had occupied the throne of Denmark since 1448.
Friederike's mother was a daughter of Landgrave Charles of Hesse, a Danish Field Marshal and Royal Governor of the duchies of Schleswig and Holstein, and his wife Princess Louise of Denmark, a daughter of Frederick V of Denmark.