Well that's definitely not an ISAbrown, the comb is completely wrong and the legs are the wrong color. So feather color is not a helpful clue to determining gender for this one. Given how small and pale the comb is I'd say it's likely a pullet.
If we knew what hatchery they came from we could...
If they're 8 weeks then I think all of them are likely to be pullets. Wonk and Coco have female specific coloring, and everyone else has nice small, pale combs.
If the white chick is an ISAbrown then it is definitely male. However, I would expect the comb and wattles to be much more developed, especially compared to the known pullets pictured. So that brings the breed of the white chick into question.
What hatchery did they come from? Also, can you...
With 16 other (dry) chickens to help keep them warm we chose to leave them be to settle in for the night. I was nervous about it, second guessing if it was the right decision, but they all came out dry and fluffy again this morning.
If you're willing to drive to Columbus I can give you the contact info for the breeder I got mine from. I've been very happy with their size and they're good layers too!