Is there any home remedy for a 4 weeks old kitten, I was given one yesterday and she has flees.

That kitten should still be with Mom. Why do you have it?

Get a flea comb (has very close-together teeth) and gently comb the kitten. I will post more on this momentarily.

4 weeks is too soon to be taken from the mother.

You should consult a vet.

Yes, the best thing to do is to call a vet to find out about the fleas and also what to feed the kitten. She can't have cow's milk.

Sadly, sounds to me like a kitten that doesn't even have a chance.

I have never known a kitten that lived through fleas. You need to get it to a vet asap and inform the cat owner to check the other kittens for fleas.
Cows milk can cause worms. They use to have milk formulated for kittens, I don't know if they still do.

I'm going to have to agree with masses here, a kitten that young, with fleas needs to see a vet, not only to address the fleas, but to check him overall, deworm him, and give you tips and instructions on how to properly care for him.
Cows milk as already stated is a no-no. It will cause diarrhea, which can be devastating to such a small kitten.
Why do you have such a young kitten to care for? Just asking.