DD is almost 9 months and sleeps in a travel cot at her GPs. They have a mattress in it, I've no idea how old. Up until now she's been in it in her sleepyhead but we've just got her out of the sleepyhead so I'm thinking I need to get a new mattress for it now. I was just wondering though does the new mattress for each baby apply equally to a 9 month old as it would be to a newborn?