Considering that I have my own molt-confirmed female that I've raised from a 1" sling, about as confident as it gets.
What size is she? If you look just above that more transparent bit of the exuvia, you'll see that dark little thumbnail shaped piece along the bottom line of the top pair of book lungs. If you take a pin and run it along the upper edge of it, it should be able to move up and down like a flap on a vertical axis. That there is the uterus externus - only present on female tarantulas and where the spermathecae will develop from.