Protecting duvet from bed wetting

[ChocHotolate]

Has anyone found a way to protect a duvet from getting wet when a child wets the bed? We use Huggies mats on the mattress which are amazing and stop the wet spreading up to the pillows but the poor duvet gets soaked.
DD (4) is dry 99% of the time and would not want to wear pull ups for the odd occasion she wets (more likely if she's poorly etc)
The problem is the duvet doesn't fit in my washing machine and it gets expensive taking it to launderette
Thanks

I've never used this myself, but what about a waterproof duvet cover?
At least then it's only the duvet cover you have to wash if it gets wet, rather than the actual duvet.

We had a DC who wasn't dry at night until about age 14.
We used waterproof duvet protectors like e.g. https://www.amazon.co.uk/Homescapes-Waterproof-Duvet-Cover-Protector/dp/B0010DUWCW/

Have two duvets and keep one ready, already in waterproof cover and normal cover, so that you can do a fast changeover in the night.

Of course you may not need to go to this much trouble if your DD will grow out of it soon!

You can get waterproof duvets

Most single duvets will fit in most washing machines even the smallest.

I'd get a washable duvet. There are even washable Cover less duvets

I would get one that does fit in the machine.

The problem with a waterproof duvet cover is that I find that they get sweaty and uncomfortable. I'd buy some cheap thin (low tog) single duvets ( you could layer up if your home gets cold) that fit in the washing machine and dry quickly or a thin duvet plus a fleece blanket.

Thank you all.
I had no idea waterproof duvet covers existed but appreciate they may be sweaty
Like the idea of layering thinner duvets.
Thank you