My name is ***** ***** I’ve been involved professionally with dogs in the health and behavioral fields for over 18 years. It will be my pleasure to work with you today.
What you are seeing is very common especially with small dogs. She needs the obedience training. I see you are 3 weeks into training but let me give you a site that is helpful at teaching owners how to train their dogs. You need to be the one who is training your dog even if under the eyes of a trainer.
The following site is helpful in helping owners train their dog. Be sure and click on the link to the page on obedience at the bottom. and links on subsequent pages leading to detailed instructions.
Training works best if you train at least 30 minutes a day (two 15 minute sessions). I would start making your dog work via the Nothing in life is free program (NILF). It is outlined below.
Secondly, she has to get off the furniture. Dogs that are allowed on furniture (even if put on the furniture) tend to feel that since they are elevated to your level or higher if on your lap, they mentally feel elevated as well in the pack order and thus are the boss. Keeping them on the floor can help lower them mentally back to a submissive position in the pack. So the first thing is to not allow her higher that the humans or even on the same level. Attach a leash and use it to remove her from the furniture. Give a correction in the form of a quick tug and firm "NO" when she attempts to get on and a treat when she starts not trying to get on the furniture. Thus you are providing negative reinforcement for the getting on the furniture and positive reinforcement for the desired behavior (not attempting to get on the furniture).
The leash can always be used to reprimand her if she growls or shows any aggression toward anyone. I know it seems like the answer is just too simple, but that is what stops this type of behavior.
If she knows the leave it command, then you can use that for the resource guarding, but while it is resource guarding, it also is a case of her thinking she owns everything instead of you owning everything. Once she sees you and your husband as the boss, you will own everything and she should not reprimand anyone which helps the resource guarding.
The following sites go over this in great detail. The last site give many different ideas and techniques to help resolve resource guarding.
If you practice the leave it command over and over with her being sure to give nice tasty treats like hot dog slices when she complies, she will be giving things up easily in no time at all.
I hope this information is helpful to you. If you would like any additional information or have more questions please don’t hesitate to press the reply to expert or continue conversation button so I can address any issues you still have . If you do find this helpful, please take this opportunity to rate my answer.