Kitten Suddenly Incontinent

I've had Winnie for about a month now and this has never happened before: Winnie peed all over herself and me in her sleep. Of course I googled it and all the scary stuff popped up so I called the e-vet. The Dr wasn't too concerned and said she probably just got very relaxed in her sleep, but I'm still concerned. I know, I should stop googling right now, so I'm asking here instead. What do you guys think?

Hmm.. I think it is strange that the vet says anything like that. To me, it sounds pretty unusual and not normal whatsoever.
I'd go to either another vet , or I would try to bring some urine first to see if she hasn't got cystitis and/or bladder stones or anything like that..
Did this happen once , and only when she was asleep?

Yes once, it didn't happen again last night. She doesn't strain at all when she goes and she goes regularly.

Does she has any other symptoms? Does she drink more often, goes to the litterbox more often, how's her appetite?

How old is she?

Over here I heard about Propalin, which is especially for urinary incontinence in dogs and cats. I don't know much about it though.

But for now I'd recommend urine testing first. It could be cystitis which is common in cats and this can be easily treated.

If they can't find anything I'd think about blood testing, especially the kidney values.

Of course it is also important to keep an eye on her. Urine testing would be the first thing to do if it was my cat. Don't know how it works over there, but over here you don't need to go to the vet with your cat for a visit. You just go to the vet with urine of the cat and in a day you'll hear if they found anything.

If that isn't the case, I'd keep an eye on her to see if there are any behavioral changes or other changes (like drinking more often etc).
And if this happens more frequently I'd go to another vet for a second opinion and blood testing.

There are no other symptoms and all her behaviors are normal. She's 9 weeks so she has to go back to the vet for another vacc anyway so I'll ask my regular vet then. I'm thinking it could have been a freak thing. She was laying in the crook of my arm on her back so hopefully she just got too relaxed. If it happens again I'll definitely get a sample (any tips on collecting urine from cats?)

Good to hear you're going back to the vet
I don't know much about incontinence in cats, they say this is not so common in cats. And if there is incontinence in cats, it's usually the older / senior cat.

But I don't know much about this so perhaps there are people on this forum who do have experience with this or know more about it. 
I do have experience with kidney disease and cystitis and bladder problems - unfortunately.
One of my cats has this sensitivity for cystitis so I regularly collect her urine and bring it to the vet to see if everything is okay. Luckily she is doing much better since she is on a special diet for urinary problems, but I do these urine testings every now and then just to make sure if everything is still okay.

Collecting urine from cats can be easy, but it can also be frustrating - haha. I always lock the cat in one of the bedrooms which is especially designed for cats, haha But...sometimes she is in there from 9' o clock in the morning and then 6 'o clock in the evening she still didn't pee. Last time it just didnt' work out so I took her to the vet and they can get some urine by doing a needle puncture.

I only do that when I just can't collect her urine because locking her for hours every time would make her more stressed than one vet visit.

Anyways, katkor works great! Most of the times I wanted urine testing, I used katkor. You can buy this online or at the veterinary clinic. You can read more about it on this website : http://www.katkor.com/Katkor_English/Collecting_Urine.html
It's cheap because when your cat pees on it , you can use it again by washing katkor with water.
The only thing is that your cat needs to pee on the litter box and doesn't wait as long as you open the door so they can go outside to pee 'Cause that's what happens over here sometimes, haha. 

I'd be more concerned if your kitty weren't still a kitten. You have a vet, you've consulted with a vet when it happened and you have a follow up/ vax appt soon. Kitty is eating, playful and eliminating waste. It's something to keep an eye on but you obviously will. I think you can probably relax and enjoy your kitty. ((Hugs))

Thanks for the advice guys! This is my first cat so I just want to do everything right and be prepared