I don't know what to do about my dog.?

Give her to your sister, it looks like she has really bonded with your sister so it looks to me that she acts like your sister is her mother. Don't worry about it, I recommend the bunny but they do poop a lot. If you think your heart is going to break, then why don't you just buy a new yorkie? Allow the new puppy to bond with you and watch how different personalities the new yorkie will have then your other yorkie. I recommend not buying from a pet store, instead if you do listen to my advice and buy another yorkie get it from a well-known great breeder, you'll find better temperaments and health in that dog.

But if you really want a bunny I would go for it, your Yorkie will probably fall into depress if your sister leaves... And the bunny will stop your heart from breaking, go for the bunny.

Sounds like the Yorkie has really bonded with your sister like she is her mother. Not much you can do about that. Best way for dogs to build up trust is with food. Perhaps she doesn't like your shoes or the sounds they make; may be sensitive to sound. Try approaching barefoot and offering a schmacko. Not many dogs can resist a schmacko. If you decide to let the Yorkie go don't upset yourself too much about it; dogs sometimes choose their (mother) owners. Sometimes there is just no ryme of reason to it. If a rabbit suits you better then probably the rabbit is really meant for you. Good luck on your decision.

Any animal becomes dependent and loving toward the one who feeds it and takes it for medium walks around the neighor hood on a leash. Study dog obedience, teach the dog tricks and play with it, it will love you.

I think you should give her to your sister. Animals can be picky on who they like and who they don't like. And if they choose to not like someone it can be for no reason at all.