But why does it matter if it is in a family or not? If there is a mentor-pupil relation involved (which is one option), then this might also be between non-family members.
This also touches upon the subject of sources. How many manuscripts do we assume the VM creators had access to? Which of the echos we see are based on imagery in other works? If it was made within a family, how rich were they to possess various illuminated manuscripts?
Edit: true JKP, but then the relevant relation would be the fact that they worked at a scriptorium more so than the fact that they were family.
This also touches upon the subject of sources. How many manuscripts do we assume the VM creators had access to? Which of the echos we see are based on imagery in other works? If it was made within a family, how rich were they to possess various illuminated manuscripts?
Edit: true JKP, but then the relevant relation would be the fact that they worked at a scriptorium more so than the fact that they were family.

