TAG,
I am not a DB counselor (ha ha had to get that disclaimer out of the way) but I am a direct person. I am also a polite and diplomatic person.

So I would tend to walk the line between directness and kindness.

Something like:
"Is there a reason you are not answering my emails?
Love, TAG"

And then let her contact you. No more chasing after her. Obviously she thinks she has the upper hand here and is using it in a particularly cruel way.

Let us know why she is not answering you.

Honey