Hi...sorry for your loss of Zuzi...I lost my Sammie this year and he was nearly 15...he barked quite a lot until the latter year when he went deaf.
As for Dustie..now 6 months old..No he doesn't bark much at all...only when startled...or someone comes to the Door...He has a funny little squeal noise when playing..but again no real barking.
We have just been away with him and some people didn't even know we had a yorkie..because he was so quiet...lets hope it stays that way.
Chris x