There are 2 Mary Stuarts princess royal:
1. Mary Stuart 1631 - 1660 daughter of Charles l married William ll 1626-1650 son of Stadtholder Frederick Henry and his wife Amalia von Solms (detail: Amaliahad been lady in waiting of Elisabeth Stuart the winterqueen and aunt of Mary Stuart).
They married in may 1641, she was nearly ten and he was fourteen. One year later she came to The Hague in 1642 but she entered public life in the Netherlands in 1644. The marriage was not consumed for several years. William led a free and happy life with other beauties until his mother (Amalia) warned him: she had been informed that Mary 's father had possible intentions to marry her off again to either the French or the Spanish (don't know this exactly anymore). As long as the marriage was not consumed this could be a threat for her disappearing from the Dutch Republic. So William had to bring an offer and slept with her. Eventually she gave birth to a son (William lll who was to become king of Great Britain: the so called Glorious Revolution).
Mary was disliked by naerly every one in The Hague for several reasons. She refused to speak a singel Dutch word at any time, she claimed to be treated as a Royal princess with a big R, she was stobbern and not very bright. Even her own family members (memoirs of Elisabeth Charlotte Palatine and Sophie Hannover) made fun of her insisting to get preference above all other royals in The Hague.
Allthough her husband was indifferent to her she seemed to have fallen for his good looks and charms but he died in 1650 aged 24 (small pox). A few months later she gave birth to a son, William lll. A hell of fight broke out for custody over William lll, Eventually a commission became responsible for his upbringing and Willam lll was "child of state and especially the States of Holland).
Mary and her mother in law Amalia where enemies. Allthough Amalia had been a driving force to marry her son William ll with Mary Stuart but moreover for her own prestige and that of the House of Orange.
As far as I can tell Mary Stuart had no special bonds with her son, she died in London and I believe reading somewhere that she even didn't leave him anything. Amalia, William lll grandmother, watched over him during his years. Only untill 1672 William lll role became more important after becoming Stadtholder and leader in fighting the enemies that threated the Dutch Republic (1672 the so called uear of disaster for the Dutch because of being attacked from the Germans, the French and the British).
In the end William lll married his cousin Mary Stuart daughter of James king of Great Britain. He and his wife became king and queen of Great Britain. Allthough Mary Suart (ll) was not very keen of marrying her nephew and cried out loud when she had to leave to live in The Hague, the Dutch liked her and she learned to appreciate her husband and eventually loved him.
