Yes, thank is correct Jennifer. James Butler, 4th Earl had sons who were James Butler 5th Earl , John Butler 6th Earl and Thomas Butler, 7th Earl.
Lady Margaret Butler who was the daughter of Thomas Butler 7th Earl, married William Boleyn and was the mother of Thomas Boleyn, father of Queen Anne Boleyn and siblings..
www.thepeerage.com shows these relationships
http://www.butler-soc.org/society/pp/0003
I'm not sure this link will show up. It is from The Butler Society webpage for members. Evidently, Thomas Butler the 7th Earl did marry a second time.His first wife had daughters Margaret and Anne and second wife Berkeley had daughter Elizabeth. The second marriage and two other daughters are not on www.thepeerage.com.