Truthfully, you haven't had this dog very long. If you're going to have to give up on her, now is the time to do it, before she bonds with the family. Yes, it's true that you haven't given this dog long at all to adjust to life in your home (and calming pills really shouldn't even be in the picture yet), but it also doesn't sound like you are equipped to address this dog's issues. Someone else will be, and she will find a wonderful home.
I have worked in animal rescue for years, and while we always try to work with our adopters, sometimes the animal just isn't compatible with the family. It happens. You don't keep an adult dog in your family that is biting your children unless you have enough experience in dog training to know how to address it, and even then it's risky.
There are a tons of rescue dogs out there that will fit your needs, especially if you aren't limited by size or breed but are open instead to the personality of the dog regardless of breed. Speak to the foster mom of your Yorkie to see if this particular rescue can help you, but if not, check out petfinder.com. Apply to lots of rescues with specifics about what you need in a personality of a dog instead of applying for specific dogs. This is always how I approach adoption, and although I've actually never gotten the breed I specifically wanted, I've always found the perfect dog. If you apply for a personality instead of a specific dog, the rescue can work with you to find the dog that will fit with your family, instead of trying to see whether your family fits with a specific dog.
If you do get another dog, whether a rescue or a purchase, your first stop needs to be at a professional trainer's, so that you can uncover any potential issues and recognize how to address them.
Good luck.