I have had a look at the LDS index and Isabella Thomson Wilson was born in Muiravonside, Stirlingshire, on 15th August 1848. Her parents are given as Richard Wilson and Eliza McNie. So far, so good. I could not find an entry for Richard and Eliza's marriage on the same index. That does not mean they were unmarried (all baptisms and marriages were not recorded), but might have been.
What you have to do is (1) look at the original entry for Isabella's birth to see whether her parents were married, where they were staying and who witnessed the baptism; (2) find her in the 1851 census to see the family group she is with and to get information about the ages and birthplaces of he parents; (3) follow the family through the subsequent censuses; (4) find the death certificates of her parents to get their ages again and details of their parents. I notice that your chart said Richard died in 1833. As he had a daughter in 1848 this is a mistake. I have proved that three people on your chart are correct. It is quite possible that the others are too, but the dates may be slightly out. Your m-i-l has given you a good start, you just have to systematically work through it confirming or correcting details as you find each piece of evidence.
Graham.
