My Yorkie has the same proplem!
I have to have him in a leash almost all the time, when he's going to run around i step on his leash, then he stops.
Try to have her always og a leash, to start with always hold the leash and make her follow you around, then she can't go run around, then start to let the leash drag after her when she walks, then put a shorter leash on and then finally take it off.
It works for me.
Then just give him lots of excersice! does she get enough excersise ?if not thats propably the proplem.
Yorkies are very energic dogs, if they dont get to walk much and run around they start to be really hyper.