Sarah Marie
Welcome to the site hopefully I can help a little
I could see only one Catherine Kearns married in Wicklow in 1868 according to familysearch.org
Catharine KEARNES (of Ballinacarrig)
Ref: Rathdrum 1868 Volume 2 Page 932
Page matched to Thomas DOUGLASS (of Kilnamanagh)
further searching found:
they married in Kilbride Roman Catholic Church;
Bride’s Father
Pat & her Mother
Bess Lenihan ;
Groom’s Father
William & his Mother was
Mary Byrne;
their witnesses were
Denis Douglas and
Bridget Kearns.
I am assuming this is the family you are researching.
As it is Catherine's sibilings you are looking for you may have the following, but here goes anyway.
They are on the 1901 Census:
Thomas & Catherine with two sons,
Patrick J. (born Rathdrum 1881 Jan-Mar Volume 2 Page 599 died Rathdrum 1910 Jul-Sep aged 30 Volume 2 Page 619) and
Thomas (no obvious correct birth record; there is a Clement Thomas in Rathdrum 1885 Jan-Mar Volume 2 Page 923 that may be him)
and Thomas Snr.’s brother Denis (possibly witness at marriage)
http://www.census.nationalarchives.ie/pages/1901/Wicklow/Dunganstown_West/Ballinameesda_Lower/1814853/Thomas Snr. looks to have died in 1905; Rathdrum Oct-Dec 1905 Volume 2 Page 657 aged 75
And on the 1911 census:
Catherine is alone and states she is married 37 years which is out by a few years which I wouldn't mind, she had 2 living children of 6 born alive which ties with Patrick & Thomas Jnr.; Denis is shown with a nephew Robert Douglas elsewhere in Wicklow (Denis died in 1913)
http://www.census.nationalarchives.ie/pages/1911/Wicklow/Dunganstown/Ballinameesda_Upper/895872/First I would assume that
Bridget Kearns the witness at the marriage was Catherine's sister as a start.
You could follow up on Catherine & Bridget using her parents names in a site like Rootsireland or findmypast.ie these are paid sites but have many records for Ireland available and let you search using parents names and most available information
The 1901 census states Catherine was born in Wicklow but the 1911 states she was born in Wexford. As she could only read according to the 1911 and the enumerator may have asked her where she was born and she told him Wexford whereas whomever filled in the form in 1901 may have just written Wicklow, it is difficult to say for sure, especially when Ballinacarrig is her residence when she married; This is in Wicklow near Brittas Bay.
Not sure any of this is new or of use but hopefully something will help keep you on track - good luck
