Hi Jean,

If you have exact dates of deaths for the family members you could ask the local council/s cemetery department for the lair details for their deaths.
This will tell you who/when bought the lair and who is buried in the lair and when they died. It also tells you the lair location which you could use to see if there is a headstone.

Have you tried going through the local newspaper/s to check for any intimations for the family?

tata

Alex