Principality of Lippe
Armgard married secondly 4 March 1909 at Oelber, Brunswick to Prince Bernhard of Lippe-Biesterfeld (1872–1934), a younger son of Ernest II, Count of Lippe-Biesterfeld, regent (1897–1904) of the Principality of Lippe, and his wife, Countess Karoline of Wartensleben. The marriage was then considered morganatic. Thus, Armgard was created "Countess of Biesterfeld" () on 8 February 1909.