My maltese isn't as tiny as your yorkie, but she is tiny, in my opinion. Emma is just under 4 lbs, and Miko is almost 11lbs, and I have no problems whatsoever with them. He is very gentle with her, even though she's a big bully to him
Emma pushes Miko around. But Miko came first...We had him for almost 3 yrs before we got her. What size is the yorkie that you're thinking of getting? I think it depends on the new pup's temperament...If he's extremely fiesty and much bigger, your little one might get hurt by accident, but if he's docile and friendly, I don't think you will have a problem. But if you're really concerned about size, I would get a pup that's at least 6-9 months old or maybe a little older to make sure that he will stay the size that you want.