Pixie is too cute!! I have seen a lot of differing opinions on here from the experts but I can tell you about my little furbaby...
Max's ears were half flopped and then went up at 4 months. They were completely up and then one stated to flop (a little) at 18 weeks. It decided to go back up and is now all the way up at 21 weeks.
So, I think you have some time before you need to worry about taping.
I like the ears both ways and think it makes a Yorkie so interesting that they go through a lot of changes. I think I saw a post on here that said Yorkies are like a box of chocolate.
I'd have to agree and I love it!!