I recomand to use the gray thing from toiletpaperrolls, cut it like the ear is shaped, put it in the ear and tape it to the ear, then the ear has some support (but only use tape that is made to be attached to fur, the one that doesnt take all the hairs off)
I did that with mine.
Yorkie ears dont go up after 5 months, so i recomand to do this as early as you can
The dog does not hurt himself of this.