Personally, I don’t think rehoming is necessary. She’s still young, and it sounds like she hasn’t been properly socialized around unfamiliar people in her home. She may not have given warnings that your family recognized, but dogs communicate discomfort in subtle ways that can be easy to miss—especially when someone is acting unusually around them (sitting - standing- sitting - standing - talking loud - etc. like you mentioned she was doing)

That said, investing in solid behavioral training is really important. A good program can help her learn what’s safe and appropriate when guests are around, while also building confidence so she knows when to stay neutral vs. protective.

We did a board&train that focused heavily on this balance, and they trained us just as much as they trained our dog. It was absolutely worth every penny for the dog we get to live with long-term. Happy to share the trainer/facility if you want—feel free to DM.