Two children play in the snow by the side of the road.
Toddles are roasting marshmallows.
The children cannot be playing in the snow if they are roasting marshmallows. Roasting marshmallows is usually done near a campfire not by the side of the road.
If children are engaged in play in the snow, then they can't be busy roasting marshmallows.
Two children and toddles can be different age groups