Sarah Cooper who reported his death is probably his daughter.
This is looking very likely. Sarah Elven, baptised 1797. How odd, though, that informant Sarah wasn't described as "daughter" on the 1845 death cert.
1851 marriage (Norwich)
Sarah Cooper to Henry Tilney
1860 marriage (Norwich)
Sarah Tilney (widow, age 56, nurse) to William Marsham. Spouse's father:
Francis ElvinImage:
https://www.familysearch.org/ark:/61903/1:1:NXNB-CDPSaturday 22 July 1865
Norfolk News "On Sunday last, at New Lakenham, in the 67th year of her age, Sarah Marsham, many years nurse to the late Dr. Lubbock, of this city".
Older newspaper report:
Saturday 10 December 1842
Norfolk Chronicle
Tragic Occurrence, CROOKS PLACE "... to send for the nurse employed Dr. Lubbock to attend the deceased. A good deal of discussion took place in the mean time. Sarah Cooper having been sent for and brought into the room, was sworn, and stated I am one of Dr. Lubbock's nurses..."
Looks like Edward Lubbock, Esq MD died in March 1847.
"The Late Dr. Lubbock. Edward Lubbock, the subject of the following notice, was the vounger son of Richard Lubbock, , Esq., M.D., who for many years practised with unusual celebrity in Norwich. His early education was received the Free Grammar School, ..."