If you are looking for a way to make bathing fun for the kids why not consider getting wet rooms instead of bathrooms? Wet rooms make bathing and showering fun for kids as they are able to splash as much water as they can around the room without causing any damage.
If you have young children who like to shower and bath together what could be better than wet rooms? Wet rooms mean that you can have as many kids showering as you can fit in them. So if you have 6 kids getting wet rooms is likely to save you a bomb as they can all use wet rooms together.
Wet rooms are easy to install and will cost o more than an average bathroom but when you consider what you will save with wet rooms installed rather than showers it makes perfect sense to have wet rooms. Here is some details on wet rooms http://www.heatandplumb.com/acatalog/Wet_Rooms.html