This cannot be true as she was born two months earlier, but she must have been conceived about the date on which Charles assumed the throne at the Restoration.

"[2] On 11 August 1674, at the age of thirteen, Lady Anne was married at Hampton Court to her second cousin 15th Baron Dacre, a Gentleman of the Bedchamber to the King.

On the same day her ten-year-old sister Lady Charlotte Fitzroy was contracted to Sir Edward Lee (raised from an early baronetcy to the Earldom of Lichfield two months before, and also a Gentleman of the King's Bedchamber).

I am so much afflicted that I can hardly write this for crying, to see a child, that I doted on as I did on her, should make me so ill a return, and join with the worst of men to ruin me.

The children of her union with Sussex were two sons, who died in infancy; and two daughters, who lived to adulthood, co-heirs of the Barony of Dacre:[6]