A female and a male each sit on the sofa with a child.
family enjoying some quiet family time
A female a male and a child sitting on does not necessarily have to be a family.  Sitting on a sofa does not imply that they are enjoying anything.
exists e1 x1 x2 x3 x4.(n_sofa(x3) & with(e1,x4) & n_child(x4) & on(e1,x3) & Actor(e1,x1) & v_sit(e1) & all x5 x6.(((x5 = x6) & n_male(x6)) -> subset_of(x5,x1)) & subset_of(x2,x1) & n_female(x2))
exists e1 s1 x1 x2 x3 x4.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_enjoy(e1) & n_time(x3) & of(x3,x4) & n_family(x4) & a_quiet(s1) & Theme(s1,x3) & (x1 = x2) & n_family(x1))