gro bag to duvet & cot or duet & bed?

[slightlyconfused85]

My DD is coming up for 22 months and sleeps in her cot with a grobag. She's happy in her cot and sleeps well most of the time so I don't want to take her out yet, but as the autumn rolls round her 1.5 tog grobags aren't going to be warm enough. They are so expensive I don't want to buy anymore so I've bought her a cotbed duvet.

Is it sensible/normal practise just to have her in a cot with a duvet and pillow, or should this be the point that the sides come off too? DP thinks do it all at once, but I'm not sure she's ready for the bed.

I started to put a sheet over DS1 to get him used to the idea of a duvet. Then moved to single duvet sideways across the cot bed (with excess underneath mattress Ifykwim)
It worked for us to go in stages, he was used to sleeping under duvet when he then moved to big bed
Doesn't now stay under it much, but happy enough in his bed!

Dd had a duvet in her cot from 1. Moved into a bed from 2. I think it's up to you and what suits your dc.