JR's have a mind of their own onaclearday It's difficult to change learned behaviour.
Try positive reinforcement when you have visitors, ignore the bad behaviour and praise her when she does what you want. Enlist the help of a friend to come calling until your dog gets the hang of things.
The lead thing is tricky, if you become anxious when another dog approaches this will transmit to your JR. Try to be more relaxed, turn and go in the opposite direction to the other dog so she learns lunging won't get her anywhere. There is no easy answer especially with an eight year old dog who has had major life changes. Love her and praise her when she is good,