Regarding Sarah George seems to be William George's sister. Still don't know who Lucy is though.
Following up David's suggestion earlier in this dialogue; there is a marriage licence index dated 6 Feb 1793 that has Robert George, bach, age 21&over, marrying Elizabeth Dunham, spinster, minor, daughter of Samuel of Wilstead; surety given by Sam Dunham, farmer of Wilstead.
Robert & Elizabeth baptised son William Samuel at Wilstead on 11 Feb 1794, and later children around Bedford parsihes. At St Johns, Martin 20/9/1795 & Charles 26/4/1802. At St Marys, Sarah 31/3/1797 & Betsy 7/8/1799. At St Pauls, Elizabeth 13/11/1809. I am assuming it is the same Robert & Elizabeth, but why would they have an Elizabeth after a Betsy - when I can't find a burial of the first one.
There are burials at Bedford St Pauls of Elizabeth, wife of Robert (at Old Meeting) on 11 Nov 1811 & of Robert on 5 Jul 1818 age 46 making him born 1772.
From a contact off Ancestry I have this information. Penelope Church, b 1811, Higham Gobion married in Welwyn, Herts on 15 Oct 1856, William George widower, b 1794,Wilshamstead. From the marriage certificate William's father is Robert George, farmer. Witnesses are George Shaw & Susan Shaw.William's residence is Houghton Conquest,Beds. Wife Sarah was buried Houghton Conquest on 3/6/1843 age 46. In 1841, William & Sarah plus a 4 month old Emma are living at How End in Houghton Conquest. In 1851 Penelope Chuch was house keeper to son William George, master butcher in Ampthill.