To tell if she's receptive you would have to show her to a male and watch the reactions. However, showing her to a male might trigger her into a reproductive cycle.
I agree with pantherenvy. I let my females go without breeding till about 1yr old. Do you have a laying bin ready and waiting in her cage? If she doesn't see a suitable place to lay when she's ready then that leads to a whole other problem...egg bound. Pay attention to her colors prior to , during, and after laying for the next time. You will also start to see her cycle emerge. Best of luck to all.