Hi,
Thank you for your message.
It may be difficult to find information on Abigail's brothers and sisters without names or dates of births. Perhaps you could try doing a search for Daniel and Mary at https://familysearch.org/
This holds a huge collection of genealogical records. If you search them for baptismal/birth records may be returned with the names of their other children.
Have you looked into Abigail's emigration much? Perhaps if you look into this and find what ship she arrived at, you could then check the passanger lists for possible siblings that may have travelled with her?
If she emigrated in the 1850's she was most likely processed at Castlegarden. You can search their database here:
http://www.castlegarden.org/
For more general information on US immigration records go to the following links:
US National Archives/Immigration info: http://www.archives.gov/research/immigration/
and
Genealogy Toolkit: http://www.irish-genealogy-toolkit.com/US-immigration-records.html
Some other webistes which may help you in your search are:
The National Archives of Ireland http://www.nationalarchives.ie/genealogy1/genealogy-records/introduction/
The National Library of Ireland http://www.nli.ie/en/family-history-introduction.aspx
The Public Records Office of Northern Ireland http://www.proni.gov.uk/index/family_history.htm
Irishtimes: http://www.irishtimes.com/ancestor/index.htm
Genealogy Links: http://www.genealogylinks.net/uk/ireland/kerry/index.html
Alternatively you could try contacting the Kerry County Library for assistance or advise. Here is a link to their Local Studies Department contact details:
http://www.kerrylibrary.ie/local.asp
I hope that this is helpful. Remember to post as much information as you can with regard to the people you are researching. The more information you post, the more likely it is that one of our volunteers will be able to advise or assist you. Also include information concerning which sources you may have already used so others may further your search.
Kind regards,
Genealogy Support