I have Francis & Jane's Marriage certificate. They were married at St Mary's Parish Church, Reading on the 28th October 1841. Francis's age is stated as full and Jane's as a minor. Francis's father is named as Richard, a smith by profession. Jane's father was Francis Pyke a carrier. The witnesses were James Pyke and Caroline Pearce ( she later married James) On the 1851 census Francis's age is unclear it has been crossed through but has been taken as 25, which would confirm an 1826 birth. the address was 87 Ashampstead Green. I believe Francis had a brother Richard, he also named one of his sons Richard b c 1848.
The address given on the marriage certificate is 4 Nut Court, as yet I cannot find out exactly where that stood but I am assuming it was near St Mary's Butts area.
I have been looking at your Ellen Thresher in the 1851 census, she was born in 1848 in Childrey, Berks. She was the daughter of William & Ann Thresher,they were living in the parish of St Lawrence Reading, it looks like Vastern Street? possibly what is now Vastern Rd, as Ellen's father was a railway porter, that would be convenient for work. In 1861 Ellen was working as an under nurse in the household of the Vicar of Aldworth ( that's not far from Ashampstead, by the way. William appears to be working as a page in the household of Mr Henry Simmonds the master brewer and wine merchant of Reading.
Hope this helps, I am happy to send a copy of Francis & Jane's certificate if you wish.
ps in the 1881 census Fanny is the Head of the household and Agnes is referred to as Grandaughter, so if I were a betting person I would almost say case closed.