Cockerel???

[lemonstartree]

we bought 4 hens (!) last October; 3 were young (pre POL)bantams.

One is now crowing every morning , is she a he ? how can I tell?

probably
on the other hand I have had hens that crowed, but they didn't do it constantly

Most likely a cockerel. does he really throw his head back and go for it? does he look different from the others/different size comb/longer tail feathers? you have to decide whether to keep him and breed or do the other thing.

Some hens do crow. I had to rehome a nutty Orpington who thought she was a bloke.

Yes some hens do get a bit macho and crow. A cockerel is hard to miss tbh,if you have pure breed bantams then the cockerel is quite different looking to the hens,try googling images for the breed. I have this hen you can see how different the hens look from the cockerel.