Hi,
Thank you for your message.
Do you know what religious denomination the sisters were? This will help determine where you need to look for records.
Catholic:
Killavees townland belongs to the civil parish of Down and the Catholic parish of Downpatrick. Unfortunately records for Downpatrick parish do not start until 1851:
http://www.irishtimes.com/ancestor/fuses/rcparishmaps/index.cfm?fuseaction=showidrecords&CityCounty=Down&parish=Downpatrick&churchid=410
However, in the19th century new Catholic parishes were created so starting dates can sometimes be misleading. Many parishes changed their geographical spread so you may find earlier records relating to your family in the records of adjoining parishes:
http://www.irishtimes.com/ancestor/browse/counties/rcmaps/downrc.htm
Records for Saul parish start much earlier:
http://www.irishtimes.com/ancestor/fuses/rcparishmaps/index.cfm?fuseaction=showidrecords&CityCounty=Down&parish=Saul&churchid=430
As most Catholic records are held locally it may be an idea to contact the local parish priest for possible assistance. Alternatively, you could contact the Ulster Historical Foundation for assistance, however a fee may apply: enquiry@uhf.org.uk
Church of Ireland:
Church of Ireland records generally tend to have an earlier start date as it was the official church in the country at the time. Most surviving Church of Ireland records are still held by the local clergy, although some are in the National Archives of Ireland and others are in the Representative Church Body Library in Dublin. Here are their websites: http://www.nationalarchives.ie/ and http://ireland.anglican.org/about/42
Lists of these surviving registers can also be found at the National Library of Ireland.
Some other websites that you may find useful are:
The National Library of Ireland http://www.nli.ie/en/family-history-introduction.aspx
The National Archives UK ? genealogy search: http://www.nationalarchives.gov.uk/records/looking-for-person/
The Public Records Office of Northern Ireland http://www.proni.gov.uk/index/family_history.htm
Genealogy links: http://www.genealogylinks.net/uk/ireland/down/index.html
Irish Newspaper Archives: http://www.irishnewsarchive.com/
Griffith?s Valuation: http://www.askaboutireland.ie/griffith-valuation/
Kind regards,
Genealogy Support