Oops, I overlooked your comment:
"...there is a Jane Stewart (pauper) born 1807 Dunblane on the 1851 census, born 1807 Dunblane...
Children - Duncan 1842, Edward 1845, Jane 1847, ROBERT 1849 Mary 1850 all born Stirling."
Yes, this does look very promising! I searched for Edward's birth and found nothing in the IGI. I'm out of credits for SP, so I'll have to recharge.
Interestingly, I have searched for this family in 1861 and cannot find them. Edward appears in no census records post-1851 in UK, Canada or USA. There is a possible match for Duncan on his own in 1861 residing in Kincardine as a farm labourer, but that's all I can find. I wonder if they emigrated.