I guess you never want to say never but as a rule if it gobbles it'e a tom. Both sexes strut and hens can have beards. When the local wild turkey's come for a visit, every turkey I have struts all over the place. I have a Bourbon Red hen that makes all sort of strange sounds, even some that sound like she's trying to talk to you, but she doesn't gobble. I've had turkeys for 30yrs. and have never had a hen gobble.
This is the one I'm relatively sure is a boy. He is much bigger then Betty (his name is Bruce )
Here is Betty he seems more slender and less shiny then Bruce.. Not sure if you can see what I mean by Shiny..