It's too early to sex them-- Polish can take a long, long time before you can sex them accurately. And growth rates can vary in both cockerels and pullets, so size at an early age isn't always the best indicator of sex.
They also look very healthy, which isn't always the case for Polish chicks.
It really depends. Usually we look at size and color of combs and wattles in young chickens, but bearded Polish don't have wattles, and their combs are often tiny. So it is difficult to tell from photos. Around 6-8 weeks, you may be able to tell yourself. If there is red at the comb, then that may mean cockerel, but you may have to search through their crests to find the combs.At what age do you think Polish start showing indications of their sex? I’m so glad that you think they look healthy They are extremely spoiled... and loved