We just adopted a senior yorkie 2 weeks ago from Seattle! She's 10 years old! I never really thought about adopting an older yorkie....but after meeting her I didn't have to think twice!
She's been really shy, and withdrawn from my other 2 yorkies....But she bonded with me pretty quickly! She wouldn't play at all. She acted like she didn't even know what a toy was.
However TODAY all that changed!! She's been running around the house, barking her little head off and playing tug of war with my girls!!!
Every day with her is a joy!!! 
in the 3rd pic she's the one in the middle. Daizy is on her L Tulip is on her R