A young child wearing a red shirt swinging on a faux tire swing.
The child is playing with his sister.
Stating what one child is doing does not make the reader aware there is another child present which would be his sister.
exists e1 e2 s1 s2 s3 x1 x2 x3 x4 x5 x6.(a_topic(x1) & Theme(e2,x3) & Actor(e2,x2) & v_wear(e2) & on(e1,x5) & n_swing(x5) & of(x5,x6) & n_tire(x6) & a_faux(s3) & Theme(s3,x5) & Actor(e1,x4) & v_swing(e1) & (x3 = x4) & n_shirt(x3) & a_red(s2) & Theme(s2,x3) & (x1 = x2) & n_child(x1) & a_young(s1) & Theme(s1,x1))
exists e1 x1 x2.(n_sister(x2) & of(x2,x1) & n_male(x1) & n_child(x1) & with(e1,x2) & Actor(e1,x1) & v_play(e1))