Waterproof cot bed or toddler bed duvet cover

[Grendle]

Does anyone know if such a thing exists? A waterproof or anti-allergy duvet cover that goes under the usual duvet cover, but in the right size for a toddler or cot bed duvet?

I can't find one anywhere, only single mattress sized ones .

Thank you

Single waterproof duvet cover you could either cut this across the middle of the to get two smaller covers or fold it as usually a cot duvet fits in so that the top edge of the cover is along the side of the duvet.

Hadn't thought of that. Thanks for the suggestion .

I got this one in the end .