Hi Marie,
St. Ninian's isn't that big at all.
The people you mention won't be listed in any of the MI publications unless they were later burials in an existing lair which had a stone.
There are 5 Taylor stones listed in the pre-1855 Mitchell's East Stirlingshire Book and 3 out of those 5 have much later dates of death but none of the names match your people.
Personally, I would have another go at the Cemetery Records Office for a Lair/Plot number - I think you might have just been unfortunate in not getting that information. If you think about it - where would they know where to bury folk if they didn't have that info? Lots of the stones have reasonably recent dates on them but this doesn't mean these individuals are definately buried there, but I would imagine some of them must be.
One Taylor stone which shows more recent deaths (not necessarily burials) in St. Ninian's is this one:
Robert Taylor died 25.04.1910 age 60
Wife Helen Laird died 26.12.1938 age 89
Their children
Charles Laird Taylor died 20.12.1877 age 2
Jessie Taylor died 18.12.1890 age 5
Charles Angus Thomas Taylor died 13.01.1896 age 6
James Taylor died 28.03.1899 age 25
Robert Taylor died 05.06.1920 age 33
Anne