Is There A Way To Stop My Papillon From Being Possessive?

I’m afraid I’ve spoiled her…
My five-month-old female Papillon and my two-year old male Yorkie are great friends when they are playing with each other. But when my Yorkie tries to show affection to me (licking my chin, laying in my lap, ect.) my Papillon growls and bites him till he gets away. Then, she sits on my lap and prevents him from coming closer. These bites are never hard, but it’s not fair to the other dog.
When people she is not familiar with come over, she barks at them and sits by me. It can take 30mins or more for her to stop barking, unless I pick her up.
Does anyone have a method (aside from dog training classes) to get her to stop? My Yorkie can never properly have peace and lay by me if she keeps being so possessive over me.