My little shadow, Gracie, is very, very loyal EXCEPT when the grandchildren arrive or basically anyone new arrives at the front door.
Then she becomes absolutely ecstatic with the company of the new arrival.
I have some severe arthritis in a back injury that slows me down but I still force myself to take her on at least 2 walks a day. I have someone else take her on at least one walk a day so she gets to go as fast as she likes with them. I am always the one to feed her (except for the little snacks she may get from the grandchildren) When I have been sick she is always right with me the whole time. She seems to know when she needs to be the nurse dog.
Maybe your little girl feels you lost interest in her. They are very sensitive dogs. It seems strange that she would not be with you when you were not feeling well since my experience has been they are quite sensitive to illness or the pain of others. I would say bribery would work best in this instance. You know what she likes best so keep trying to win her back with her favorites.