How much do you pay a theatre director?

What’s a reasonable rate for a director of a play/revue?

I have a director who is interested in directing a show I’m doing (she has worked with my group in the past and is really eager to do so again) but I have no idea what a good amount of money would be acceptable. In the past someone else (who I don’t have the freedom of asking how much) paid her. And I think flat out asking her how much she expects is kinda off putting for both her and me.

She’d be required to be with us for 3hrs a week for 16 weeks of rehearsal until opening.

Thoughts?