first of all, welcome to YT!
Yorkies are one of the most difficult dog breeds to house train. Tucker is over a year and still not fully house broken. Here's what I suggest, get an x-pen. set it up in one room, and put her pee pads in it. When she's out of the x-pen, dont' let her out of your sight. if she starts to go somewhere other than the pad, say "No" firmly and put her down on the pad until she goes. then PRAISE LIKE CRAZY!!
Good luck! I hope you stick around, this site is really helpful!