I don't know of any source for a month and year of Anne Dudley's birth. As for the Elizabeth and Anne born in the 1660's, I suppose the reference is really to two of Samuel's daughters born in the same time period. Samuel is oldest son of Simon and Anne. Both girls died young as did a brother named Simon. From his first marriage to Mercy Tyng, only Mercy, lived into adulthood. Mercy Tyng Bradstreet died three days after Simon's birth and shortly afterward Samuel moved to Jamaica and his father, Simon, raised Mercy. Samuel married a second time in Jamaica and had at least three children who were living with Simon at the time of his will. Samuel had died sometime prior to that period.