Help - how to protect duvet?

[buggie]

Nearly 4yo DD is out of nighttime pull-ups, but is prone to occasional accidents (typically no more than 1-2 a wk), we use the pampers bed pads to avoid to much disruption to the bottom sheet, but am having a bit of a mare with regard to her duvet - she seems to manage to get it wet too (think she ends up with it wrapped around her a bit).

Have seen duvet liners on Amazon, but there seem to be lots of pretty negative reviews for most of them - Am sure we're not the only ones with this issue, so, any ideas/recommendations for what to do? (otherwise I might look at becoming shareholder in a local laundrette!).

[amydown]

We have pretty bad house dustmite allergy in our house so we use these:

http://www.johnlewis.com/john-lewis-new-anti-allergen-enclosed-duvet-liner/p439235

Not designed for accidents per se but I have found that it's quite good at keeping the duvet protected for occasional accidents.

[Convex]

Or if you are handy you could make your own from pul fabric (the stuff that modern washable nappies use?)