I too am trying to establish this family...and also wonder about the age of Mother?/...maybe grandmother.
James and Dorothy left for South Australia and arrived the in 1854.
My question to anyone is...did this mother go to? or did she died in East lothian....as she was on the 1851 census (age 82) with James & Dorothy.
Have tried to find a death in SP for this Mary Nichol....no luck so far.