I added Robert Steel (K8N6-75B) and Janet McCormick (KZ2W-SBK) and it added Jacobina Rae.
Her children have birthdates before hers. I have source for a Jack Rae (female) from Scotlands People. No other source info.
We could not see the problem that you mentioned regarding children showing birth dates before mother's birth - so maybe you have already figured out what to do.
However - just in case, this knowledge document explains how to do it:
It appears that the parents associate with Robert Steel (K8N6-75B) have been modified by another user. The name of the mother has been changed from Mary Barton to Jacobina Rae and the birth year from 1752 to 1786. As you noted the 1786 date is inconsistent with the birth dates of the children. My first thought is that maybe the Robert Steel married to added is not the John Steel married to Janet McCormick does not belong in this family. Clearly there are mixed up people that require further research and corrections.