There must be a way to modify children along with a parent ?

Example: I have modelled a couch and it consists of the frame of it and the cushions. The cushions are separate objects, with the frame, their parent.

I mirror (modifier) the couch frame - the parent - but the “new” couch is frame only. Is there a link type to the parent that will have the children follow the modifications?
PS: transformations work, eg when the I grip and move, the whole family moves along.

Thank you JA12