Note too. the presence of an aged Thomas EDLRIDGE (Elizabeth's father?) in the same house in 1841. Also the presence of a Lewin AVERY and wife Elizabeth - she had been Elizabeth BROWN, marrying in 1841 shortly before the census.
As Elizabeth ELDRED was married in Ropsley, it's possible that her mother was the Elizabeth ELDRIDGE buried there 9 Oct 1836 aged 73
This leads us to the baptism at Ropsley of Elizabeth HELDRED in Feb 1792 at Ropsley, dau of Thomas and Elizabeth.
Also to Thomas HELDRED marrying Elizabeth BINGE at Ropsley in 1786.
Who said the hilliterate haitch was dead?
The only aged Thomas ELD* burial I can find in Lincs was at Tallington 23 Dec 1846 aged 82. It's a tidy distance (20+ miles) from Welby but I can't see such a person in Tallington in 1841.