Couldn't see an 1821 Eliza Richardson born Isle of Man in the England 1841 census. Of the Elizas without birthplace given none seemed to have a David in the same entry. I only looked at 1821 births as there are a LOT of Eliza Richardsons and I didn't know which bit of England they'd likely be in! If I'd seen IOM come up I'd have checked it whatever the date. I then started looking at the IOM 1841 census, just in case she was there, when Ancestry crashed - 'run time error', whatever that means.

Sorry, and good luck!