There is an Eliza Montgomery in the 1850 US Census for Cedar Ward in Philadelphia, having been born about 1840 in Ireland, the child of Andrew (age 40) and Mary Ann (38) Montgomery. He is listed as a weaver. There was a Sarah Furry living in the household, also, aged 45. US Census records are searchable and online through Ancestry.com and other sites It is helpful to know where they settled in the US.