2 Kittens fighting over food

Question
We just adopted two kittens from our local humane society shelter.  They are now 9 weeks old and have been with us for a little over a week.  We have one dish for food and water.  But I noticed today that one of the cats wouldn't let the other cat eat when she was eating and growled at the other kitten.  Should we sepreately feed the kittens with their own dishes?  They had to share at the shelter and are sisters.  Please if you have any advice, Thanks.

Answer
Hi Amanda!  
Going to a new home is a HUGE change for anyone...especially a little kitten.  At the shelter they may not have had the amount of food you give them or they may have been forgotten when feeding time began.  Now that they have lots of food, are always fed...they are protecting what they have.  One cat in any household, brother/sister or not, is always the alpha cat.  The kitten that is growling definitely leads the pack.  There is no need to worry.  I have a two year old cat that growls everytime he eats.  While the other cats are eating with him he growls.  He never does anything more.  He is definitely the alpha cat in our home.
The kittens will adjust to your home and the growling may or may not stop.  Continue feeding them together and they will duke out the "alpha" role.  They will not harm eachother.  Cats play very rough, biting, wresting...but this is just their way to play, so don't be concerned when you see that.  It is very common for them to get too rough and you will hear one of the cats hiss or cry.  Don't stress it at all.  They will be absolutely fine!