They are all of the same age, but what IS the age? This will make a difference in telling one from another.
At three months of age going by their wattle development I'm going to say birds 1-3 are toms, and number 4 is a hen.
If they ared really 12 weeks old, I would think only #3 is a tom. They don't look that old to me, so I'm not sure they have all had time to develop. If they are only 8 or 9 weeks, #2 might also be a tom. If they are 12 weeks old, you ought to be able to see the difference in size, with the toms being significantly larger than the hens. Also, llok at the feet. Hens have more delicate feet.