Apart from the difficulty in getting a researcher, Christian Cemeteries in Pakistan are generally in terrible condition, or razed completely, due to vandalism, religious intolerance, official disinterest etc. It is very unlikely a grave would still be in existence.

Here is a 2018 article about one of the Christian Cemeteries in Lahore, there were several cemeteries

https://web.archive.org/web/20180609142512/https://www.christiansinpakistan.com/lahores-historic-taxali-gate-cemetery-in-shambles-due-to-willful-ignorance-by-authorities/ "Lahore’s historic Taxali Gate Cemetery in shambles due to willful ignorance by authorities" by Madeeha Bakhsh 2 June 2018 christiansinpakistan.com, now archived.

Should you wish to pursue a photograph, some years ago Dr Ali Jan of Peshawar was writing on British Cemeteries in different areas of Pakistan. Should you be able to locate him via social media, he perhaps may be able to suggest a contact in Lahore.

https://en.everybodywiki.com/Ali_Jan_(writer)

Edit: There is an email address at the top of the following article, which perhaps may still be current

https://web.archive.org/web/20090829075530/http://geocities.com/scn_pk/peshawar_remembered.html