A young girl with a white long-sleeved shirt on helps a young boy brown long-sleeved shirt on with tying his shoelaces.
A girl helps her brother tie his shoes
The boy might not be her brother.
The young boy is not necessarily the girl's brother.
Just because a young girl with a white long-sleeved shirt on helps a young boy brown long-sleeved shirt on with tying his shoelaces does not mean she helps her brother tie his shoes.