Travaling with à children of 10

if your child is no taller than 1.5 meters, you can buy a child ticket and have him/her share a bed with you or your husband.
but if he/she is taller than 1.5 meters, you have to buy a full price ticket for him/her, and he or she has a bed, then you three will have three beds which can not be in one soft sleeper cabin. but, you still can share a bed,