Three children, two boys and a girl, are playing with the swings on a playground with residential houses in the background.
The three children are related to each other.
Children playing together are not assumed to be related to each other.
Three children are playing on a playground with residential houses in the background don't necessarily imply that they are related to each other.
Just because three children are playing together in a residential area it does not mean they are related to each other.