Need help to create a summary of a child table in a parent table

One way is to look up the Key field of rhe Orders Table (which might be  [Record ID#] or some other field), down to the Results ta le (it's already on he Accesons table and then from there look up down to documents. 

That will mean that have three possible sources for the key field of the orders table down in the documents table. Make a formula field which will calculate the value of the Key field from the directly Related Order, or if blank, then the Orders Key field from the Accessions, or the Record ID of the Order from the Results table.

Then make a Report Link field on the Orders table and set it up to match the Key field of Orders (on the left) with the calculated Key field (right side) on the Documents table.

or the record ID from the accession or the record ID of the order from the results.