Thank you for all your replies this is very helpful to me. I cant remember what we did for my first but she took to everything like a duck to water. My son however is completely different and would take longer to adapt to the change. He is a real wriggler and i am terrifed he will wriggle under the duvet or pillow.
I think i will leave it a few months at least by then the weather will be on the change and we can start off with using a few blankets and see how we get on.
It seems that there is no general rule, even though they say they can be used from 1 yr.
I'll probably end up buying another growbag... HeyHo!!
Thank you so much for your help:)
x