Looking for ancestors

Hi, looking for any information about my Stewart and Lee ancestors.  The only information I have is that they originated from Castlebar, Co. Mayo.  Thomas Stewart was born in 1821 and married Ellen Lee (also born in 1821).  They emigrated around 1848-50, presumably during the Great Famine, to England.  The first trace I have of them in England is when their eldest child Thomas Stewart was born in Northampton, England in 1851, their remaining 2 children Mary (born 1854) and John (born 1856) were born in Daventry, Northamptonshire.  They were Catholics and, on coming to Daventry, worked in the local shoe factory.  They are recorded as living in the Irish quarter of Daventry.  Michael Lee, recorded as a farm labourer in the 1851 census, claims to have been born in County Mayo (circa 1813-1817).  His wife, Catherine, is also recorded to have been born in County Mayo around 1818.  Their eldest child, Peter, was born in County Mayo in 1846/7 which means that they emigrated in 1847/48 as their next child, James, was born in Northampton in 1848.  They arrived in England as a party of 10, included in this party was James Lee (brother to Michael), John Lee (brother to Michael) and his wife Mary and another John Lee (nephew).

Thomas Stewart and Ellen Lee may have been among this party and they are my great great great grandparents. 

Michael Lee and his family left Daventry before the 1861 Census but his brothers, sister and nephew all remained and were recorded as agricultural labourers and pedlars.  Both the Lees and the Stewarts were neighbours in the Courts (a part of Daventry where Irish families settled).  One of their descendants, Emily Lee (locally known as "Emmy" lived to be nearly 100 and is buried in the local cemetery.  I knew her as a child.)

If anyone can help further with dates or family histories, I would be very grateful.

Thank you.