if you could get a better clearer comb shot of both might be able to it that way. in the first pic the one in the back looks like it has a more flat comb which could indicate a pullet and the other looks like its comb is raised and looks like it may have 3 rows of peas which would indicate a cockerel
Light brahmas are the exception of females having the 3 row comb. The females in this color have much bigger combs then any other color. This color is very hard to sex until 14-16 weeks when saddle feathers come in. You have 2 girls.
My LB had a bigger comb then yours and I have a pullet. I don't know her exact age.
4-5 weeks? She had a red comb early.