A Carey on the throne of Scotland?

George Carey (1547-1603) was the eldest son and heir of Henry Carey (1526-96) and his wife Anne Morgan (1529-1607). George Carey was therefore the nephew of Catherine and Francis Knollys, Catherine being Henry Carey's elder sister. This Henry Carey was first cousin to Queen Elizabeth through their Boleyn mothers being sisters; Anne and Mary Boleyn. George Carey was therefore a Boleyn and Howard relation with familial connections to the Queen.

George Carey, 1601

In May 1568 Mary, Queen of Scots fled to England and was presently placed into the custody of Francis Knollys. In October of this year, it was proposed that Mary be married to a member of the English nobility, as this would permit for English help to be given to Mary for the restoration of her throne, with the security of future friendship with England. Queen Elizabeth specifically told Mary that she could not marry unless the match had the majority of approval of the English nobility, as well as her own consent. At the conferences in York concerning this matter, Francis Knollys put forward his nephew George Carey for the match.
On the 15th October 1568 Francis Knollys wrote to the Duke of Norfolk, mentioning the possibility of marriage between his nephew and the Scots queen, with wording of a manner which indicated that the idea of this marriage initially came from the Duke of Norfolk;

"my Lord of Hunsdon would be offended by my marrying his son in this behalf, and therefore I pray your Grace to use the matter thereafter"

Francis Knollys wrote to William Cecil on 20th October 1568 asking George Carey's name to be mentioned when discussing the future of Mary of Scots.
Francis Knollys also wrote to his brother-in-law Henry Carey on the 27th October 1568 discussing the matter.

"I thought this Queen, to have her Majesty's favor, would not stick to marry one of her Majesty's near kinsmen of the mother's side, if she liked the person and quality of the man. And I assure you I suppose she would be well content to match in this case with my cousin, George Carey; or if her Majesty like not of an elder brother, I think she would not refuse one of his younger brethren, if her fancy could like of his person and other circumstances." —Bolton, 27 Oct. 1568. 

This suggestion however was not favoured by George Carey's father Henry Carey, nor by the queen, and Francis Knollys had the blame for the match placed upon him.

George Carey, 1581

Two years later in 1570 the queen had changed her mind; this marriage would prevent Mary from marrying a foreign power or a nobleman in England with great power, such as the Duke of Norfolk. Therefore, Queen Elizabeth offered Mary her freedom from imprisonment on the condition that she marry George Carey and name him King consort of Scotland. William Cecil made the journey to Chatsworth in October of 1570, where Mary was living at this time, in order to persuade the Scottish Queen to accept the marriage to George Carey. Mary of Scots refused this match.