Andrew has a single duvet on his toddler bed... It is ok width wise the length totally hangs over the bottom by quite a way though. I couldn't find a winter duvet for a reasonable price in toddler size which is why he has a single...
Sophie has a combed duvt and I got it from eBay... Brand new in packaging for about 20 quid but that is the duvet, pillow and one cover set for pillow and duvet. Sophie has peppa pig and Andrew had toy story but there are a few to choose from.
Asda also sell them and b&m sell the package ones but ithink I have only seen Winnie the pooh ones in there'd but they also sell the covers
Hpe that helps! If you have a single for jayden maybe try that on her bed and see what you think?