I am in a quandry about buying a new cot bed mattress for my second child. She will use the same cot as my now 4 year old had.The mattress is a sleepright Mothercare one with a removable cover which has been washed. My baby is now 5 months old and ready to move into the cot. I am getting conflicting advice and would welcome comments from others to help me with this situation. What did you do?