I've never dealt with food aggression in a dog that old. When we got Adele she was around 3 months old, and she had food aggression towards the other pets, not humans. Basically I just reinforced that she was at the bottom of the hierarchy and used NILIF.

BUT, I didn't feel threatened putting my hand in her food bowl, etc, because she wasn't aggressive towards me. Is this puppy agressive towards her owner, or just the other pets? I still seperate my dogs when they eat. Most of the time, it isn't a problem, but Adele has attacked Marta over a rawhide before (luckily this was when she was a puppy, nobody was hurt and now I know better and crate her with anything like that).

I know that the money is an issue, but if she wants to keep the puppy I would suggest at least talking with a behaviorist. Food aggression can be a very serious problem, especially since she has so many other pets. Sorry I can't be more help.