Our dominant tom was certainly an early bloomer. He was gobbling WAAAYYY early. If I remember correctly, he was only 8 weeks old when he started gobbling. So, he was an obvious one. We had no idea that we had any hens until the one started acting "sick". Since these are our first turkeys, we really didn't know what to expect. I was expecting them to put their wings out like the chickens do, as "handles" for the males to stand on. When it was just droopy wings, we thought she was getting sick. Then, we caught them "connecting" the next day, after she was acting "sick" when I started petting her. Hoover (dominant tom) came up and just started humping her, lol. Usually, if I sit down or crouch, he'll strut and dance for me, trying to impress me, so I didn't think anything of it when he came up doing his sexy dance, lol.
They certainly are a harder to sex critter! I've thought about trying to vent sex them, but there's just no way I can flip a bird that's 20+lbs and prod around without getting injured or hurting the bird I'm violating. The beards don't help any either. BOTH of my white birds (which I now believe to be hens) have beards.