You may pray in those rooms as long as you are not facing them in prayer. Dolls are allowed for children. The same applies to hanging pictures on the walls, as long as they are not of leaders (religious or otherwise) for fear of developing a spirit of hero worship or undue feeling of adoration; in which case it becomes akin to shirk. But if they are simply family pictures you are allowed to pray as long as they are not directly facing you in prayer.