[kjc]

So sorry to hear about this event... I'm thinking, in addition to what Ladyjane has said, that something about you may be triggering a bad memory for her.

As this is the internet and I cannot see you or what is going on, I am going to make some suggestions that may seem a bit silly, but may be worth a try. And as I am totally ignorant of any customs and/or cultural issues, forgive me in advance if I cross any lines, as anything I say here is not intended to offend in any way, shape, or form. Here goes.

First, I want to address physical appearances. Do your maids wear uniforms? Could you dress to appear to look like one of your maids? I'm only saying this because there is something about the maids that makes your dog feel safe, obviously. Could be a skirt opposed to slacks or jeans, all one color as oppossed to a more vibrantly colored outfit. Anything you can see that makes you appear so much more different then them? Hair color or style? Wearing/not wearing eyeglasses or sunglasses? Hats or scarves? Consider anything that may be obvious to the dog.

Next, think about how you smell. The soap you use, perfumes, hair products, skin cremes, deoderants, hand cremes, anything like that can be reminding her of a previous owner. I don't normally wear lipstick unless I'm going out, but I put some on one day to help with dryness, and my dog acted like I was a different person. He kept sniffing my mouth... it got a bit weird but the only thing I could figure is that he really liked a person in his past that wore lipstick. He seemed more relaxed in a sense, just the opposite reaction your dog had when you yawned.

I'm not sayng you have to change who you are, but if you can find either a good trigger and play on it (like the lipstick in my case), or a bad trigger and avoid it, that would be a good start.

Another thing to consider is dog to dog behavior. When you yawned, did you cover your mouth with your hand? I'm thinking maybe not? Dog to dog, the showing of teeth can be seen as threatening behavior. Until she trusts you implicitly, you may have to be careful with certain behaviors that can be misinterpreted. Staring into her eyes can be threatening, also. When she's acting terrified, don't look directly into her eyes, look off to one side.
That she exposed her tummy to you is a submissive behavior on her part, and very good. When you yawned while she had her tummy exposed, she may have thought you were going to attack her. I'm refering to the most base, instinctive level of communication between two beings at this point. Other things to consider is how much above her you are. Getting down on the floor with her will be seen in a friendlier light, than if you hover over her.
Dogs that have been physically abused will be reactive to fast movements of hands and arms, and feet and legs. Until she's more comfortable, I would tend to move slowly and deliberately around her so she can't confuse what you're doing.

When she approaches the maids, what are they doing? And what do (did)they do to entice her to come to them?

Most all Yorkies are more respondent to a high pitched, almost squeaky, mouse-like, child-like voice. You could try different types of voices to see which she likes best, and use it during stressful (for her) times, and play times too. I think bc they are small dogs, they can relate better to higher pitched voices.

As she is new to you, does she know any commands, like 'sit, stay' or 'Go lay down'? Try different phrases till maybe you hit on something she understands.

My last adopted dog really scared me on our first day together. I started to pick her up to put her off the bed, and she let out a low, rumbling growl. I was so unnerved by it at the moment, I decided it was best if I walked away because I truly felt fear and I didn't want her to pick up on that. I went into the kitchen to compose myself and figure out how I was going to handle her if she did it again. I went back into the bedroom and tried again and as soon as my hands were on her she started growling again. I acted shocked, and said (in a high pitched voice) 'What? You don't growl at me! Silly puppy!' And I laughed. I call it 'Laugh Therapy'. For one, laughing will relax you. Secondly, she will sense this, and feel less threatened, than if you speak sternly to her. If you do this, be careful not to show her your teeth. This can be difficult and you may have to practice in the mirror, so you can see exactly what she'll see when you do it.
Then, too, you'll have to aclimate her to a human smile. Start with minimal teeth showing, just for seconds at a time, just occasionally throughout the day at different times. As she becomes less reactive, show a bit more teeth (bigger smile) a little at a time. This can take weeks to months, but it prevents tense situations, and possible bites.

One last silly thing. Whenever I accidentally hurt my dog, as in snagging a knot in her hair while brushing her, she would turn to attack me. I have found this with other dogs too. If you apologize verbally to them, it has a good effect. And I mean go all out. Like " OMG! I am so sorry! Did that hurt? Oh you poor, poor baby! I didn't mean to hurt you I'm so sorry, Are you Okay?' And use a high pitched voice, try babytalk, whatever you can do to mend the situation. This can work in other situations too. "You're soooo pretty" got me out of a tough grooming session that was quickly heading south!

Have treats too, with you all the time. Ask your vet if she can have like Cherrios, any fruits (apples) or vegetables (carrots, green beans). Find something she really likes.

Bonding can happen quicker too if you talk to them like you would talk to a child. Just include her in the process of whatever you're doing.

Hope this helps..