One child pulls another, sitting in a red wagon, along the sand.
a boy and a girl play
There is nothing about a child pulling another that implies that either of them are a boy or a girl, or that they are of different genders. The act of pulling a wagon does not necessarily imply play.
exists e2 e1 s1 x1 x2 x3 x4 x5.(n_sand(x5) & Theme(e2,x2) & Actor(e2,x1) & v_pull(e2) & along(x2,x5) & in(e1,x4) & n_wagon(x4) & a_red(s1) & Theme(s1,x4) & Actor(e1,x3) & v_sit(e1) & (x2 = x3) & n_thing(x2) & n_child(x1) & card_eq_1(x1))
exists s1 x1 x2 x3.(a_topic(s1) & subset_of(x2,s1) & n_play(x2) & of(x2,x3) & n_girl(x3) & subset_of(x1,s1) & n_boy(x1))