What counselors say in the sessions is usually a suggestion. It is your home and you ultimately decide what goes on there. Your daughter at 19 is considered an adult and has to display the responsibilities of an adult. You can consider either 1/ give her a time frame during which she can prove herself, 2/ let her know this is your home and the dog may get more attention and care at another home. It is not the dog's fault; the owner has to discipline and teach it what is expected.
You are not rocking the boat. You're making sure that your daughter is a responsible adult. As far as the ADD, that ought not to always be considered a cause for someone's behavior. There are always going to be cases when the behavior is driven by something else- opportunism, habit, trying to get away with things, irresponsibility/relying on others, etc.