Kids grow up. Kid’s furniture- not so much. Sometimes you have to take things into your own hands. Like converting a crib into a desk. Assuming you have this style crib (and not one that converts to a bed), it’s a fairly simple matter of setting the crib base to the highest newborn level, removing the railing on one side, and then cutting and laying down mdf/particleboard where the mattress would go. Add some blackboard paint and hooks and accessories and you’re done. Very creative re-use, and not too difficult to DIY, especially if you already have other matching furniture in the child’s bedroom.