Water in rear diff/rear wheel gears. White oil

Hello all, I am new to the forum so greetings.

I have just serviced my daughters 100cc Peugeot Kisbee twist and go on 2016.

Easy enough to do, but this is the 2nd time I have changed the diff oil in the rear wheel. The old oil was milky white which suggests water. Trouble is apart from a breather coming off the gear case and going in to the back of the air filter I can’t see how water is getting in. It’s not leaking oil.

many ideas please? Thanks

 

It could be just a bit of moisture from airbox as you say but whenever i drain my gear oil it's never clean,I never change gear oil anyway, I've had my Typhoon 19 years now and have only changed oil a handfull of times, fitting gear kits etc. I don't worry about the colour as long as it's got some that's ok with me !