I'm not related to this family but my family came from County Mayo so I thought maybe I could help.
If you go to www.familysearch.org
, you can look for Bridget's birth information to help you narrow down the search to a place.
Looking at http://failteromhat.com/griffiths.php
you can search for the Tomas name in County Mayo and it has 10 results which is good because it narrows your search.
Then if you go to the Ireland Census at http://www.census.nationalarchives.ie/
and search the Tomas name in Mayo, you will find 34 results in 1911 and on the 1901 census you will find 18 results.
Also, you can look at the current Irish phone book online at http://www.eircomphonebook.ie
and find 5 listings for Tomas with addresses and phone numbers in County Mayo.
On the 1911 Census, there is a Patt and a Thomas in Belderg More, so maybe they are her brothers.
With this information, hopefully you can sift through it and figure out your answers. I hope this helps.