I worked with Marvin, the Mealy, a lot today. He has balance issues, but if you support him he's happy to be out and about. He is sweet to most, but not everyone.
His liver bile something or other tests were normal, and the vet had said that he was a normal weight for a mealy.
His age is unknown. He is open banded. He seems elderly. He has not been sexed, and if I had to guess, based on behavior, I'd say Marvin is a hen.
I suppose it's possible that he backs up into my arm like a presenting hen does because he is trying to balance, but his actions seem hen-like to me. I'm not an expert at all, though, but generally if a bird really likes me, it has turned out to be female.