It's so hard to get a good picture of a black cat! But if that one's back end looks like the other boys, then he's a boy too. But I think I kind of see some indications that it's a female. Try to post some more pics of the black one, maybe one of the pics will magically have more contrast, lol.
Thank you, we are keeping one of the tabbies and the black one so we will be able to keep an eye as they get older, my friend is having the other 2 tabbies so at least I have it confirmed they are boys