Catherine Duggan 1828-1884

[Torwoodlee]

Hello,
I don't have very much experience in researching relatives in Ireland and I was wondering if I could get some advice.  I would like to find out more information, if possible, about Catherine Duggan born around 1828 in Rosscommon.  Catherine immigrated to Lancashire England with her family when she was in her teens.  She ended up marrying a Thomas Fitzpatrick in Prescot Lancashire on 21 October 1846.
Her father was Patrick Duggan born around 1800 and he was a labourer.  Her siblings were Margaret Duggan 1836-1856, Mary Duggan 1839-1901 and Michael Duggan 1844-?.  Her younger siblings, Mary and Michael were born in Prescot Lancashire.
I would like to know who Catherine's mother was and if it is possible to go any further back?  Also, I would like to know if there were any other siblings as the family seems small; I expect that there may be more siblings.

Thank you very much
Borderslass