I am trying to find the correct death date of my Eliza Whiteman

[maddys52]

Looks like John Henry POLLARD died 31 Jan 1918 at 113 Ray St Heanor. Adminstration to Elizabeth Hannah POLLARD, widow.
https://probatesearch.service.gov.uk/

Modified to add:
John Henry POLLARD and Hannah Elizabeth and family are at this address in 1911.
https://www.familysearch.org/ark:/61903/1:1:XWS7-2JG

[maddys52]

I would have thought it more likely that Mary Ann FISHER (daughter of James FISHER and Mary nee WHITEMAN born 1866) married David ILLINGWORTH on 31 Aug 1885 at St Peter, Leeds. On their marriage certificate she is aged 20, father James FISHER, miner.

you have Mary Ann FISHER in 1871 at Denaby:
https://www.familysearch.org/ark:/61903/1:1:VBZM-5BX

In 1881 at Leeds:
https://www.familysearch.org/ark:/61903/1:1:Q27T-VH5M

[maddys52]

Meant to add earlier - Mary Ann FISHER birth registration at Basford march qtr 1866 mmn WHITEMAN.

There is also a Mary FISHER birth registration at Basford June qtr 1866 mmn NEWTON.

The Mary FISHER who presumably married John SMITH Mar qtr 1866 registered at Basford always is just plain "Mary" in censuses, whereas the one who married David ILLINGWORTH is "Mary Ann".

Such a common name, it's hard to know definitely who the wife of John SMITH is without obtaining the certificate. (As I mentioned earlier, the certificate for Mary Ann FISHER and David ILLINGWORTH is on Ancestry, and it definitely has her father as James, a miner.)