female staffy becoming over protective of puppy!

My 6 year old female staffy has always been great with other dogs, they have attacked her but shes never attacked them, when I bought my now 7 and a half month old female staffy ruby, she has started becoming pretty protective outside when we go for a walk, she never use to bother with other dogs she use to just walk past, now she goes up to them and is normally fine, but when they come to her she just snaps and walks away never bites. The other day another female staffy that has attacked my 6 year old staffy before had its hackles up at my puppy, then my 6 year attacks it, once I had got hee away her staffy lunged at my very submissive puppy, what should I do?
Also my 6 year old bes had a phantom pregnancy when we got ruby.

I have no experience in this sorry, apart from advise perhaps walking them seperately for a bit. Rachel will probably be able to shed some more light for you as she has experience in behaviour

I thought of doing that but I dont know how the puppy will act because shes always been walked with the other dogs, I have 4 dogs, 2 english springer spaniels and 2 staffs one of the staffs being the puppy.
Thank you though :-)

walk them seperately for a bit the older staffs probably feeling anxious i do love spaniels think they're amazing dogs.

The spaniels are brother and sister from seperate litters there 12 and 13 and still bonkers, only problem with spaniels is they roll in alot of bad smells and they catch alot of rabbits and squirrels, had some traumatic experiences with baby rabbits and squirrels and the spaniels tbh

This is literally a recipe for disaster - why do you have your dog off lead around a dog that has attacked her before? Why has your dog even been attacked by others dogs so many times? If she is snapping, she's clearly uncomfortable. Just because she hasn't bitten before doesn't mean she won't the next time. I think you need begin to learn to read your dogs and manage their behaviour/protect them from others before an accident happens. Patricia McConnell is a brilliant writer for canine behaviour.

We didnt realise it was that dog as it was differnt people and it looked like a puppy, and she was attacked when she was a puppy alot, the dog that attacked her has attacked other dogs, and she hasnt bitten another dog after that that was the first time, we went through a pack of dogs yesterday and she was playing with them, and how can you protect your dog when there dog is out of control runs up and attacks your dog?

I understand that it is difficult to protect your dog when an off lead aggressive dog approaches - but you say that she has been attacked a lot? Especially as a puppy, that's bound to make her a little "off" with other dogs.

Well she got picked up by the harness when she was about 16 weeks old she got shuck and it tore all her ear by a rhodesian ridgeback, and a few weeks after that 2 staffs attacked her, and she just avoids them but it worries me because she should interact shouldnt she? Thanks for the help btw