About W sitting
W-sitting is when a youngster sits with their legs out in front of them and their ankles and feet on each side of their hips, forming a characteristic W shape. Doesn't it appear to be uneasy? However, youngsters have more internal hip rotation and total range of motion than adults, so it's unlikely to be painful.
You may not need to discipline your youngster if you only observe them in the W-position on occasion. Keep an eye on them to determine if they can easily move out of the position and if they change positions throughout the game.