In 1641, when only four years old, she was engaged to Count Enno Ludwig of East Friesia. However, later on she broke the engagement as she regarded him highly unsuitable. Also in 1641, her brother, Prince Willem II, still only a boy, married his child-bride Mary Stuart. The
marriage was an honour for their family and only had been allowed because of the support the House of Orange gave the embattled King Charles I of England. After the execution of Charles I, his son, Charles II, became an exile on the continent and much of this time was spent in The Netherlands.
During this time a romance developed between Henrietta Catharina and Charles II, one which was quite serious as has been revealed in letters Charles II wrote to his friend, Lord Taaffe. However, he did not hurry their relationship until, on 3 September 1658, Oliver Cromwell died and Charles II expected to return to England as its monarch. He proposed to Henriette Catharina but she became ill with emotion. By November it became obvious that thinking of returning to England had been premature, and so Henriette Catharina's mother took matters in hand.

Henriette Catharina was then introduced to a German prince, Johann Georg II, Fuerst von Anhalt-Dessau and, in July 1659, was made to marry him instead of the penniless English adventurer. Ironically, Charles II returned to England in 1660 to become its 'Merry Monarch'.
Henriette Catharina and Johann Georg II produced ten children. Her marriage appears to have been happy and she created a Dutch centre in Anhalt. She also remained in close contact with her sister, Albertine Agnes, who, at the age of thirty, had become a widow. This close contact would eventually result in the marriage between one of Henriette Catharina's daughters and Albertine Agnes's son.
However, on 25 March 1696, Hendrik Casimir, Henriette Catharina's son-in-law, died as the result of war wounds. This broke Albertine Agnes's heart and she died two months later on 24 May 1696. As a result, Henriette Catharina had to educate her own children as well as assist her widowed daughter in Leeuwarden.
Shortly before her own death, she had the satisfaction of seeing her Dutch grandson being accepted as Stadhouder of Friesland as well as becoming the heir in The Netherlands of William III, King of England. 

Source: Leo van de Pas