Any behavior changes signal a thorough vet check up, with blood and urinalysis, first thing.
IF you get a clean bill of health, she's likely bored and feels unfulfilled. Yorkies have a strong work ethic, were bred to be working dog. She doesn't have a job, doesn't have good, hard, fulfilling work to do to look forward to so she creates something to do, ways to interact with you as she can.
If this were my elder girl, I'd ad a daily work program to teach her some simple obedience skills so that she feels she is working toward learning her skills, her ability to perform the tricks or skills you teach her. Go online and study 'positive reinforcement dog training techniques'. Use a happy, upbeat body attitude, big smiles and happy voice when you give her commands, and instantly reward getting it right, gentle sad-face 'uh oh' if she misses - so she has feedback to know why she doesn't get her treat. Yorkies just eat up positive-reinforcement training and love to work, love to excel at it!
As she works with you to form a working team, she'll begin to get her daily dose of oxytocin, that bonding feeling formed in our and our dog's brain anytime we look at each other or smile or interact. It's sometimes called the mommy hormone - the hormone we secrete in our brains when we hold and bond with our children. Well, we make that hormone when we interact with our pets, too. They also make is. Google it and you'll see they've done studies to support this statement. Dogs produce and become addicted to their oxytocin fix. You will, too!
She'll want to please you to get more of that and more good feelings and pleasure that you create when you praise her genuinely from the heart as she learns more skills. You can't fake praise - you want to MEAN it so that she feels your involvement with her so be sure to make eye contact when you praise her. As she learns her skills and feels her job is to work with you learning her obedience sklils/tricks, she'll likely feel more fulfilled, happier and make fewer weird demands.
Be sure you take her for a good, long smell-walk as often as possible. Where she has time to use her doggie nose to get to smell all those wonderful, mysterious scents outside along the way as we walk. Take the time to allow her to visit over each scent, really get into it if she wants. They say dog's smelling new scents is like our watching a new Netflix series or reading a text message or email - it's great fun, highly rewarding for them.
Play hide-the-toy or hide-the-treat games with her and praise effusively every times she wins. She'll love it!
Enrich her life and she'll likely repay you as a much more easy-going, fulfilled pet.