The double marriage alliance between Prussia and Brunswick by her marriage to Charles I, and that of her brother Frederick to Charles' sister Elisabeth Christine, led to a permanent alliance of the most important North German Protestant houses in Prussia and Brunswick.

[1] The family ties of the two dynasties resulted in the alliance of Brunswick and Prussia in the Seven Years' War, and the career of Philippine's sons in the Prussian service.

[4] The Duchess pursued, partly because of the influence of the ducal adviser Johann Friedrich Wilhelm Jerusalem, the German intellectual life very closely.

[8] She raised her son Charles in reverence of her brother, Frederick of Prussia, gave him a humanist education with Abbé Jerusalem among his tutors, and sent him on a Grand Tour with the archaeologist Winckelmann as his companion.

The Swedish Princess Hedwig Elizabeth Charlotte described her, as well as her family, at the time of a visit in August, 1799: Our cousin, the Duke, arrived immediately the next morning.