Given names tend to be repeated as middle and first names down through history.
1691 - St. Michan, Dublin, Parish Register of Baptisms, page 301, b.1 October 1691, William son of Christopher Carroll, cooper, & Mary his wife.
1682 - St Michan, Dublin, Parish Register, page 141, b. 7 May 1682, Mary daughter of Christopher Carroll, cooper, & Mary his wife.
1841 Dublin Almanac and General Register of Ireland, Pettigrew and Oulton's Street Directory 1841, page 669 has the following entry;
"Henry Street -47 1/2 Christopher Carroll, carver, gilder, and looking-glass manufacturer"
1841 Dublin Almanac...Classification of Trades, page 812, "Rutland-Place, Green-lanes, Christopher Carroll, road contractor"
1739, Registry of Deeds, Dublin: Abstract of Wills, Vol I, 1708-1745. Entry at page 596 reads: "Warren, Christopher, Dublin, upholder, 26 March 1739. Narrate, 3/4p., 30 Feb 1739/40. His wife Elinor Warren, exor. His brother Patk. Warren, exor. His sister Mary Doyle also. Warren. His sister Rose Kean als. Warren, her husband. His brother Michael Warren, gent. His sister Mary Carter. Walter Codd, Dublin, merchant, and his wife Catherine Codd. Mary Carroll, Dublin, wife of Christopher Carroll, her mother Mary Plunkett, widow....." Therefore one assumes that the maiden name for Mary is "Plunkett" like her mother.