She did not have the chicks vaccinated. It cost another $2 each.
In most breeds the roosters comb is definitely red. At least redder than the females. You might look up photos of your breed to see the differences.
Wow! $2 is a lot for the vaccination--my chicks that I get from McMurray get vaccinated for 17cents each for Marek's and another 17cents for cocci....as a side note here, i have been very happy with McMurray, the quality of the birds has really surprised me. The Polish have the biggest crests, really fluffy and round and dense, much bigger than the top breeders on here that I have gotten others from, and really good dispositions..and they are sexed female. After going through 12 chicks last year to get 1 white crested black, they either ended up males or cuckoo...so I ordered the sexed female from McMurray, 8 of them...and they were all female and proper color, with really pretty crests.
On the gender question, if you can post pics we would love to help you guess! Each breed is different, but between all the people on here that have raised chicks that turned out to be boys, I bet we can figure it out