Not really rare, happens all the time in the genus. All of my females "growl" at the boys. I like to think that they are akin to gals from Cavan, John.I thought i would go on record with this because most people don't believe female terribilis call. In the past 2 days I have witnessed a female yellow terribilis call in response to a male. These are Frye line yellow terribilis, bred by Shawn Harrington. They laid their first known clutch about 2 weeks ago and a second tonight. The female's call is very different to the male's call. When I first heard it I thought it was a very loud male tinctorius call but since I've only got one terrarium in my living room, I knew it had to be from the terribilis. The female repeated the call a few minutes later in response to a male. Today's call was also in response to a male. It is not quite as loud as a male but it's a lower tone, almost monotone. Very much like a very loud male tinctorius only lasting about 1-1.5 seconds, if that.
I'll try to get it on video if I can, but it seems to be a rare event.