I believe they're both hens - the caruncles (neck bumps) would be larger in toms. I think toms get their beards at three / four months? However, keep in mind that hens can grow beards as well. Uncommon, but it does happen.
The top one is Muffin, the mother. You can see that an adult has much less brown than the juvenile (middle one). She was that brown last year as a juvenile too.
The middle one is Cupcake. He is about 13 weeks old. Then the babies are Cheesecake and Flapjack. They will be two weeks old tomorrow.
It's very possible that she could be. The narri gene is sex linked recessive. So any Tom that comes from a mixed background could be carrying it and would throw it to half of his daughters. (Well, and half of his sons, but they would just carry it and not show it.) In this way, the narri gene could stay hidden in the male line for several generations. So your breeder could think he had Rio Grande breeding stock, but may not know the background on them.
(I know nothing of Rio Grande inheritance or what they even look like. Guess I could look them up.)
Ahh ok I see. From what I've seen the rio grande are basically wild turkey color and feather patterns. Some are darker than typical wild turkey but basically the same.