Might be just a coincidence of names, so just to note for now the following baptism of a Bridget Roberts on 7 January 1837 in St. Patrick's RC parish in Kilkenny city, for parents Laurence Roberts and Ellen Nolan, the sponsors were Toby Butler and Mary Branall (about halfway down right page):
https://registers.nli.ie/registers/vtls000635371#page/153/mode/1upEdited to add: I think the Bridget who was baptised in 1837 may have died young, for I've noticed a second Bridget (
'Bid.') baptised for this couple, same parish, on 8 September 1841, the sponsors were John Lawless and Mary Maher (about halfway down left page):
https://registers.nli.ie/registers/vtls000635371#page/176/mode/1upSame parish again, maybe an older sibling called Mark baptised 1 July 1831 (near bottom of right page):
https://registers.nli.ie/registers/vtls000635371#page/124/mode/1up1 Mark Lau Roberts Ellen Nolan
Sp James Egan Cath MaherWith the usual health warning about potential inaccuracy, there is tree on the 'Ancestry' website that shows whom I think is the same Mark Roberts marrying an Ellen Kearney in Durham in 1855, having a son Lawrence Joseph Roberts, and continuing to live in Durham, however the link from Mark to a younger sibling Bridget Roberts is not shown.
BTW, on the off chance, have you heard the surname Dalton mentioned on Bridget's side? Reason I ask is that a Bridget Roberts married a Nicholas Dalton in St. Patrick's, Kilkenny, in February 1863 - no fathers' names recorded. Ignore this Dalton line, I have since been able to exclude them.