The little girl is helping her little brother get soap out of the dispenser.
The little girl is washing her brother's hands.
Just because she's helping him get soap doesn't mean they are washing hands, they could be playing in the soap.
exists e2 e1 s1 s2 x1 x2 x3 x4 x5.(n_dispenser(x5) & n_brother(x2) & a_little(s2) & Theme(s2,x2) & of(x2,x1) & n_female(x1) & n_girl(x1) & a_little(s1) & Theme(s1,x1) & of(e2,x5) & r_out(e2) & Theme(e2,x2) & Actor(e2,x1) & v_help(e2) & Theme(e1,x4) & Actor(e1,x3) & v_get(e1) & n_soap(x4) & (x2 = x3))
exists e1 s1 x1 x2 x3.(n_hand(x3) & of(x3,x2) & n_brother(x2) & of(x2,x1) & n_female(x1) & n_girl(x1) & a_little(s1) & Theme(s1,x1) & Theme(e1,x3) & Actor(e1,x1) & v_wash(e1))