I have asked myself the same question a million times. I do thing they try in subtle ways to control us and I think that we allow it because we don't want to make too many waves.
Could you either tell her you need an established time, and choose one that works for you, or text her first simply asking when she is coming instead of waiting on pins and needles?
"Acceptance doesn't mean resignation. It means understanding that something is what it is and there's got to be a way through it."--Michael J. Fox
