Here's the reality: a chicken - even a mean rooster isn't always a match for a dog or dogs. Not even chihuahuas. It could maybe take on one, but if they teamed up, I don't think so. So you seem to have limited options. One would be to build a safe place for them to be where the dogs can't get at them. Another would be to ask your step-mother if you could work with her dogs around the chickens, then do your research on how to train a dog to leave chickens alone. Personally, I would not count on this working, because when you get two or more dogs together, they sometimes forget everything they know and break all the rules anyway.
You cannot count on the dogs leaving the chickens alone if they get attacked "just once" by a rooster. It may set them off and make it worse. My last dog caught a squirrel once when he was about 6 months old. The squirrel reached around and grabbed the dog's nose and wouldn't let go. Instead of making my dog avoid them, it just increased his hatred of them and he chased and caught many more squirrels almost until the day he died.
Maybe you can do chores around the place or something to earn enough money to buy fencing for your chickens. This is really the best thing you can do for your birds. A turkey may or may not help, either. It could kill your chickens. This is what happened to a friend of mine. Good luck. I hope you can work out a solution.
