Food aggression-help please!

Sophie the Leo pup is now just over 3 months old and is very sweet and adorable and GIANT-35lbs last week!  However, she is very aggressive with food and I do not know how to handle it.
For those of you who don't know, we have 3 other dogs and we free feed from one bowl.  I have NEVER had an issue with any of the dogs being aggressive or competing for food.  If one is eating, the others will wait or stuff their noses in and take what they want, no problem. The same goes for table scraps and treats.
Sophie was getting fed separately, in her crate, but would not eat in there so I put her food by the other bowl.  She not only snaps and growls at the other dogs (and cats!) when they go near her food, she won't let them near their own.  If anyone else tries to eat, even if she's asleep, she'll get up and chase them away. 
She is getting increasingly bad about it and bit Chicklet (who is 3.5 lbs) today!  If I feed her treats by hand, she will bite me in her haste to get it.  I am trying to teach her "easy" but am tired of being bitten- she broke the skin on the back of my hand.  She does NOT growl or snap at me if I take her food dish or put my hand in it.  Can anyone help?  I do not want her to turn into a giant food aggressive dog so I need to nip this in the bud!

I free feed multiple dogs but also have multiple bowls down - when I do have food aggression with a new dog I just separate the bowls farther away- she can't guard bowls if they are in 2 different rooms!  I also would use a squirt bottle and when she is snapping and snarling at the other dogs blast her- she needs to stop this now and getting a face full of water when she goes to attack another dog will definitely change her perspective on things.  She is still a baby and this should be easy to fix  Binky's suggestions are great too- there should be no reward for rude behavior!

I am no help with free feeding - I wish we could do that in our multiple dog house, but....  We have 2 Mals and were warned that food is a touchy issue with the breed.  We also have an Alaskan Husky who I swear is ADHD and anorexic.  Free feeding would have caused a major war in our house so I originally feed each with their own special bowl, but at the same time. UGHHHH Talk about wild.  Racing and competition were insane.  After a battle that actually made me a bit nervous (between the mals) I began feeding individually.  Life is soooooo much better.  In our case it is definitely a breed issue and as I have said we were warned.  Now everyone eats more slowly and no one rushes and everyone knows the routine so there is no upsetment.
As far as treats our Jadis was rough and a nipper.  We did the closed hand - but we also tried a wide open hand - allowing the treat to be flat in the palm - and that worked really well.  After a few days of working on "leave it" at puppy school, we moved back to the closed hand and then to a normal hold.  SUCCESS!  She now takes a cookie without the nip.  I can treat all at once - as long as they all are in the sit or down position without their noses touching.  The house rule is "don't throw treats" - make sure they are directed at a specific dog and hopefully we are using their name - then all is well!

Good luck - I am envious of the success you have already had with your others - I am sure your newest will figure it out and work with the others!