I'm hoping the specialist will find it is something very minor and easily fixed. I'll be thinking about you and Chelsea.
I know it's not the same type of procedure but when my late bullmastiff went through chemo about halfway through his first 6 month protocol the oncologist and his tech said they'd rather do it with us in the room since he seemed more relaxed and less stubborn. He'd just put on the brakes and flop, and 135 lbs is a lot to move when he didn't want too. I know yorkies are more easily manuevered, but hopefully if you tell them she'll be calmer they'll let you back there. I'm sure she'll do fine either way though.