Full question: What sort of accent did Anne Boleyn have? I know she was born in England but at what age was she sent to France?
There don't seem to be any descriptions of the way Anne spoke, only of her appearance, but she may well have spoken with a slight French accent.
If you believe that she was born around 1501 then Anne was around 12 when she was sent to the court of the Archduchess Maragret of Austria, Regent of the Netherlands who was fluent in French and who had spent much of her childhood in the French court. Anne then spent the years 1514-1521 at the French court.
Anne spent the first 12 years of her life in England, in Kent, surrounded by English speakers and English accents, so her English accent would have been well established, but speaking French from the ages of 12-20 may well have left their mark and given her a slight French accent.
If you believe Retha Warnicke's birthdate for Anne being 1507 then Anne was only 6 when she left England and would surely have picked up a French accent.
Anne was known for her French style and French ways so may well have spoken with a French accent, this woud indeed have made her different and made her stand out from the other women at court.