After the trials and tribulations of patch 1.50, I can finally give you my score.
Mary and John Jones both completed their LTW and had a unique LTR each = 2x2 = 4
Of their 11 children, 5 moved out = 5x3 = 15
Of the remaining at home, 1 completed her LTW and had a unique LTR = 1x2 = 2
And the final 5 didn't = 5x1 = 5
The total is 4 + 15 + 2 + 5 = 26