You might be right about the parents, although I can't be positive. As they grow a bit, it may become more obvious, or they may always be a bit of a mystery. The crosses you name should have single combs. If the chicks grow any other kind of comb, that would mean at least one parent has a non-single comb.
For determing sex, you will probably have to wait until they grow some more. Males are often obvious around 6 weeks of age, because their combs & wattles get bigger and redder than what pullets have. But some males become obvious at younger ages than that, while others can keep people guessing for much longer.
Crowing can start anywhere from a few days old (very rare) to about 2-3 months old (pretty common) to 6+ months old (fairly rare.) Of course any bird that lays an egg is a female, but the males usually become obvious before their sisters are old enough to lay.