http://www.ourfamilyhistories.org/getperson.php?personID=I149062
http://our-royal-titled-noble-and-commoner-ancestors.com/p3175.htm
I'm sure in searching their names, you will come up with a dozen different answers. These days Circa means somewhere near that date, but I've seen it take in a span of 30 to 50 years in places. It seems to be a standard way out when an exact date is not known. The dates on the profile are confusing, but I would imagine it depends on the source of the info they have.
Good luck, Robin
Katherine Leake(Peck is listed as b circa 1520 ,Joan Peck her mother b circa 1493 and her father John Avery Peck b circa 1490 http://www.geni.com/path/Judy-Rice+is+related+to+Katherine-Leake?fr...