Hi Ann,
I hope this will help you out. I have a William James Stanley, b: 1798 at Bethlem. He married a Rebecca Susan Sandys, b: 1802, in 1835. She died in 1837. Her parents were Robert Sandys & Mary Bouchier.
He married Anne Sandys on 30 May, 1837. Her father was George Sandys. (no further info on him).
William James Stanley's parents were James Henthorn Stanley, b: 1775 & Eliz. Ireland, b: 1776.
James Henthorn's father was Edward Stanley, b: 1748 of Low Park, Roscommon, married to Lydia Bacon.
Edward, b: 1748 father was Edward, b: 1725 at Low Park, Roscommon.
Ann & William's children were - George Richard Sandys Stanley, b: 1840, Dorothea Mary, b: 1841 & Nehemiah Bonchier, b: 1849.
Ann Sandys' father George may be the one you are looking for. If I can be of further help, let me know.