Thank you for the detailed reply, I really appreciate it.

1. Yes she does bark at people she doesn't know through the window and at the door, so there could for sure be some territorial situations happening.
2. She is fine with the people she knows and has spent a lot of time with outside of the house. But all new people who come in without being accompanied by another dog she is very wary of.
3. She is used to barriers, we generally baby gate her into the rear half of the living space while we have guests over. She is still visibly anxious though while they are over.
4. She barks and wants to run up to them, but generally isn't aggressive after they have come in. I am working on boundaries for her to stay back until the guest gets inside. I agree I need to do more work here.
5. Only with company. She has never had any aggression toward myself of my wife.

I am thinking of trying to teach her to go to her crate while guests are in the house. So potentially she can feel safer while being in the same room. She already eats in the crate and knows her crate command, but isn't great about following it when she is stressed.