Joyce, you've got a terrific dog! Holly, our lab, has good instincts too. She has been hanging around me a lot lately knowing that I haven't been feeling well. Usually she is PODH's dog but I've not been feeling well and she's been checking on me...
We used to have a Cocker Spaniel, Boeing. A bit tempermental, to say the least. When PODH wasn't around, no one got past that dog. Otherwise, he could care less. One day, I was out in the back yard working and one of the guys who had been doing to fence repair work for the past week showed up and I thought Boeing was going to take his leg off. Don stopped dead in his tracks. Looked at me and said, PODH isn't home is he? Nope. No big deal with this guy, but he knew right away and said, you've got a great watch dog. Up until that day, Boeing had been following him around, playing with him and his guys, etc. But not that day! Weird little dog!
(In case you are wondering who PODH is, ask Sally!)