Hello and welcome
When it comes to the Sheps you are in good hands with Occy.
I would just like to add that the growing signs of protection agression need to be dealt with swiftly. Things could escalate within days ( and I am not being over dramatic when it comes to this) and she could be a potential danger to any person who enters 'your' space .
It's a common enough thing and often misunderstood behaviour in rescue dogs.
She has had it tough.You found her,saved her,nurtured her.....you inadvertantly became hers .
As you say,she is your shadow.She see's it as her job-her need- to protect you you at all cost.Understand also that jealousy is also a very real emotion in dogs,she will no doubt be beginning to feel this as well. Not only will she see Danial as a potential threat ,she will see him as a potential intruder into hers and your space/relationship.