My database of Lawson families indicate Alexander and Agnes Mason had at least 7 children all born in Tulliallan between 1824 and 1840. I do not know what happened to their parents but all 7 children appear in the 1841 census in Tulliallan in the household of Janet Mason aged 30. There are no other adults present and I do not find any of the children in Scotland after that time apart from possibly Agnes who is niece of a Mary Dawson in Clackmannan in 1851.
I do not have any further information of members of this family in Australia.
My web site www.yorksgen.co.uk/forums/portal.php
is open to all Lawson researchers around the world. This is a forum based site and you are invited to join. Hopefully you will also post some information on one of the Lawson Forums. Doing so will open all my on-line searchable databases for you giving access to over 330,000 individual Lawson records.