New pit puppy with issues?

We recently rescued a 12 week old white pit mix. She is super sweet but seems to be showing some aggression type issues. We have three other dogs and always have had dogs. We haven't had a puppy in our home in many years. The last two were a yorkie and chihuahua ant that was about twenty five years ago. Our other current dogs are a senior lab mix, three year old lab/probably pit mix and a senior poodle/Maltese mix. The senior lab pretty much ignores the puppy, the lab/pit plays with the pup for the most part but the poodle hates her. The poodle has always been grumpy and doesn't seem to like any of the dogs having fun. He was a puppy mill dog and we just have always accepted his issue. This morning the new girl and poodle got into a scuffle that seemed pretty serious. I'm almost 100% sure that the poodle initiated it but the pup was definitely not backing down. Also, a couple days ago, the pup was snarling when our la mix got close to her food. For the most part, she is happy go lucky but these action are concerning. At her age it just doesn't seem right.

any thought on this

Thanks, Kate

New pit puppy with issues?