My Kittens are four weeks old, and the mother is still nursing them.. I have put food out for them, however, the mother quickly eats it... If I keep putting food out, she keeps eating it all... Is it to early to wean them?

I hope you are feeding her kitten chow... she needs the extra nutrients. In my opinion 4 weeks is a bit young esp if mamma is willing to nurse them. I would leave them alone for a while. My opinion is that mama knows when her babies need to be weaned. But if after awhile you want to introduce them to food. Moisten some and get it runny and rub it on their lips, you may want to do this while she is out of the room.