If you have two kids, but only one bedroom for them to share, problems are sure to arise. Having two bedrooms might get rid of any kind of fighting, but if that's not an option, then making a room divider might be a better idea.
A room divider can be made in many different sizes and can be made to look like a wall, but features extra storage for each kid. It's an easy to do project and should help with any problems you have. So check out the tutorial, be safe, and good luck!