I'm with you..If you don't know the age for sure, then we're going to have a hard time with this bird. So you think about 11-12 weeks old? I say could go either way right now. Having a better idea of age would help as we could know whether or not the hackle and saddles should be in. Pattern could be a pullet or could be a cockerel. Comb is pretty big and red, so makes me think cockerel.
If it was 3 weeks old on the 11th of May it would be 12, almost 13 weeks old.
I would lean more towards cockerel, but the red in the wings do not look really patchy enough to make me fully confident that it is a boy.. Also, the comb is smaller than I remember it being at 13 weeks. I still lean more towards boy.