There comes a time when it becomes clear that children, who have comfortably shared all available accommodation for years, would be happier in separate rooms. Even children of the same gender may differ enough in personality, interests and habits to become very tired of sharing.
So at this stage, provide them with bed-sitters, so that they can do their own thing in the privacy of their own room.
The best way to prevent yourself from constant worry as to the whereabouts of your older children is to make it easy for them to bring their friends home. This means arranging for conditions in which they don’t have to make conversation with you all the time, so a room that isn’t just a bedroom is all-desirable.
The bed will have to serve as the sofa/lounging area for entertainment purposes, and the bedcovers or counterpanes will come in for some hard wear. A spare bed (perhaps a stacking one) is a good idea to put up friends from far afield; it is one of the delights of bigger girls to have someone to stay and to giggle with.
Bedroom-type storage should, if possible, be unobtrusive, although a lot of hanging space is usually needed. Storage for smaller things could be kept low and include a surface for doing homework. Perhaps you could run a counter-height surface all along the wall and provide simple storage facilities underneath, such as a low chest of drawers, and something like a simple office filing cabinet for hobbies that need space, like stamp collecting or dressmaking.
By the time that children have reached the bed-sitter stage, they will have a taste of their own. It may be frightful, but it must be considered; to ban everything that you don’t consider impeccable does not guarantee that they’ll grow up with faultless tastes of their own; they’re that much more likely to rebel against yours as soon as they have the opportunity.
It is also useless to expect your children to have the same feelings about neatness as you have. So don’t blanch at displays of whatever they collect – just keep the door shut and realize that a tidy room is far more unnatural to most young people than an untidy one. Messiness, in any case, is a passing phase, and provided that there is enough storage space, strewn floors and heaped chairs will miraculously clear – in time. All you need is patience and understanding.