Ok so lets back up here for a moment. It is advised a puppy stays with it's mom and litter mates until they are 13 weeks old. In this time the mom teaches her babies many things, one being bite inhibition, the litter mates play a big part in this teaching process also, they are taught when biting is to hard by mom and litter mates. Being taken away from mom and litter mates can cause anxiety in some pups.
So lets take it from here, your baby is 10 weeks old, she was taken from mom to early thus the hard biting, and separation anxiety. Now you have to take on the roll of yorkie mom and teach her when biting is to hard. Always have a toy handy when she gets crazy, out of control and biting, give her the toy to bite.
Keep in mind she is only alive only 70 days, she wasn't born with knowledge, this world is new and exciting and she is a wild thing that now has to be taught how to be civilized, the mom would have taught her that, also the breeder would have started pad training the puppies. Because the breeder didn't want the extra work she sells the puppies to soon. Now you have to be the teacher. You must have a lot of patience with the puppy praising and high value treats when she does what you want, no yelling, hollering when she does something wrong, but do correct her in a positive way.
You cannot take her to work with you until she has had all of her vaccines. To be a ESA you need a letter from a doctor or psychiatrist, you should keep a copy of this letter on you in case you are asked for proof. You cannot just say the dog is a ESA. I am sure you needed something to show your housing the dog is ESA if no dogs are permitted.
The dog also has to be properly trained to behave under all circumstances and conditions around her, in other words, she has to be a good fur citizen.
You cannot compare her with other dogs or other yorkies you may had had, they are not clones, each have their own personalities, no two are alike personality wise.
So, you have a lot of work before you, work on one issue at a time, she is to young to have a lot of bad issues corrected piled on her at one time. Terriers have a short concentration span, work with her no longer then 5 to 7 minutes, after 7 minutes they are no longer focused on you or training.