A woman in a black jacket and a black and white striped skirt is watching a woman talking to a little boy sitting on concrete steps.
A person is talking to a child while another person watches.
A woman is a person talking and a woman is another person watching her talk to a boy who is a child.
A woman is a type of person. A boy is a type of child.
If a woman is watching another woman talk to a little boy then she is another person watching someone talking to a child.