Question, do your family come over unannounced via the back gate, without really knocking at the front door. I say not really knocking as the dog didn't hear it and we all know dogs will always run to the front door.
I would never do this unless I was expected and the house I was visiting had said just come round the back. If I was unannounced and noone answered the door but both cars where in the drive I would call and say I'm out the front.
I feel that it is a lack of respect for me and my house, pls keep in mind I don't have the best relationship with my mother, and she always oversteps any boundaries that I put up as I am the daughter and she is the mother. She has the mentality that as she is the mother she can do whatever she likes as she is always correct. There is no reasoning with her believe me! It's not just me, but my brothers feel this too.