Using Family Search
http://www.familysearch.org/eng/default.asp
I found an ANN JARMY Christened 27. 1.1788 at Trowse, Norfolk the daughter of Edmund & Hannah.
Also ANN JERMY Born 2.11.1796, Christened 6.11.1896 at Sprowston, Norfolk, daughter of John Jermy & Mary Chester.
Do you know when your GGF Henry Jermy Miller was born, as this would give a starting date to look at death records and censuses?
A Nathaniel Miller was buried 18. 8.1847 at St John Timberhill, Norwich, as was an Ann Miller on 12. 5.1822
I haven't been able to trace the birth of any likely Ruths, but perhaps someone like Craft1948 may be able to.