Thanks - so if the dad is possibly a mix, then I can't really go off of the chicken calculator or depend on the barring to indicate roosters, right? I do agree that they seem large and have larger combs than pics of pullets I've seen that are that age. I do see little spur buds beginning on one of the dark ones, or else I'm imagining it!
We have some flexibility in finding the roosters homes (we are renting while house hunting since having returned to Austin but my brother-in-law has 10 acres and I can put a mobile coop up there). So, if it comes down to it I'll just keep them all there until they definitely all look like roosters and then try to find them a home (except one to keep for myself). They all seem very sweet so far. My daughter bathed them all last night and trimmed their wings and they were docile as usual. It was a poultry salon!
Many thanks for all of the help,
Shannon