Glad you've joined us. Please check the forum for William Douglas 1610 - 1682 for a few suggestions I've made about finding the real ancestry of William (it's on the 2nd page). There is also a link to Leslie Mahler's article from TAG concerning Anne Motley's family. If you have questions or suggestions after looking over all this, let's discuss them.
The more information you can give about the people you mention, the more chance there is of someone else connecting with your family.
Dates and places of births, deaths and marriages all help to place families.
Professions also help.
'My great-grandmother mother was a Douglas from Montrose' does not give many clues to follow up! But a bit of flesh on the bones makes further research possible. But if we are told who she married, what his profession was and where the children were baptised, then we can get to work.
Maybe it is time to update the information in your profile?