Well THAT is reasonable isn't it??

You are the older and therefore more responsible one. DD2 didn't talk for a long time. Didn't have to, DD1 told us what DD2 wanted. She's still telling us what DD2 is thinking, even when she is wrong, wrong, wrong, at 25 and 23 years old. Can't let go of the ruler role she carved for herself.
I'm the middle kid. Took Mom some long time to figure out my younger sister was goading me until I hit her. I got in trouble for that a lot.
I don't know yaks, but are his nails in need of a trim?
Are they pushy to get their spot in the "pecking order" or actually aggressive?
Attach a torsion bar to it and crank it upwards