I think the first steps are probably searching for the marriage of Catherine & John, and depending on the details found on that, searching for Catherine's baptism and her parents marriage. Unfortunately there are no Wicklow marriages available online at the moment.
It would probably be worth confirm the exact address for the family by a birth cert for Thomas but based on the Griffith's record mentioned the Carton family lived in the townland of Brockagh, which contains the town of Laragh.
for RC Parish records :
Civil Parish : Derrylossary
RC Parish : Glendalough
Townland : Brockagh
Details for this parish are available on Microfilm Pos. 6474 in the National Library in Dublin and contain baptisms from June 1807, and marriages from Jan 1808 (some missing dates between 1838 and 1840).
Ralph Carton is listed on Griffiths at site 29f, and the details are not very clear on the maps, but site 29 is just over 1km to the west of the centre of Laragh town, and just before the Y junction. The on the other side of the road is listed as a Lawrence Kavanagh - possibly a relation to John ?
Shane