There is a James Sullivan age 7 listed on the 1881 census in Newport, MON as follows: James Sullivan, age 30, laborer, born Pontypool, wife: Ann age 31 born Bantry, Ireland, Son: Daniel age 12 born Cardiff, Mary A. age 8 born Cardiff and James age 7, born Cardiff. They were living South Ward. This is from Ancestry.com. A lot of Irish came into South Wales during the Potato Famine for work and it is possible that your Sullivan family was one of them. Good luck. Annie