Is my owl finch intersex

Got an owl finch as a friend for my canary because they're so cute. Her name is Pinchi and at first I thought she was a male as his chest bands were quite dark compared to his siblings in the store, and then as she grew she started to sing and dance so then I was certain. But low and behold one day I find a finch sized egg in the big seed bowl that had been cleared of seed. Wtf?? She sat in the seed bowl sometimes but I just thought she was just a bit weird as female finches shouldn't sing?? I googled around and found nothing, so I thought if humans can be intersex both hormonally and physically, can a finch? Also the egg cannot be my Canary Chuu's as he is a male, sings, and hasnt laid any in the past two years(I got Pinchi one year after him and its almost been a year). She stills sings and dances and sits in the seed bowl. She's also very active and healthy 🙂