Both heelers and German shepherds are actually herding dog breeds, not livestock guardian breeds. They have a much higher prey drive than true livestock guardian dog breeds, which were developed for low prey drive and high nurturing behaviors. Even with a livestock guardian pup, it is not advisable to leave them unsupervised with poultry or stock until they are much older and responsible. A 6 month old pup is like a child and it is easy for play behaviors to escalate into chasing and other prey behaviors. Eating dead poultry does not lead to chasing and attacking live poultry. It is pretty much play and play is fun and self-rewarding. I would not leave them alone at all. The best
course of action is to confine your pup in a pen next to the poultry and only allow contact when you are supervising. The easiest and best solution would be to have your dog patrol around the poultry enclosure and not in it. I'd give her lots of time and prevent any more chasing or worse accidents. She can be a good farm dog outside the enclosure. If the poultry is free-ranging, you will probably have to build an safe enclosure for her.
Since your dog is a herding other than livestock guardian dog, she may never truly be reliable with poultry and I wouldn't risk it until she is much older and you have been able to determine if she is going to be reliable. Guarding poultry is the most difficult task we ask of dogs since their flighty behavior can be exciting for dogs. Even livestock guard dogs were developed to protect stock not poultry.