That lady was lying to you regarding Brahmas taking longer to hatch. Yes, a LF chicken may be just a bit longer than a bantam. But, all chickens take 21 days to hatch, on average. If she can't be trusted with this information, I find it difficult to trust anything that she has to say.
Your eggs look fertile. However, they look delayed. Please go to learning center and read "hatching eggs 101". Your thermometer needs to be calibrated. I use a good medical grade thermometer, either digital or mercury bulb, which has guaranteed accuracy. (usually +/- .2 degrees). Place thermometer in cup or bowl of water at 100*F along with what ever submersible thermometer you are using in the incubator. Don't let thermometers touch sides or bottom of the bowl. Give thermometers time to level out, and then compare the readings. If your medical thermometer reads 100*, while your other thermometer reads 98.5*, you know that your other thermometer is reading 1.5* low. Take that into account as you adjust your bator.
Also, beware that your bator may have warm/cool spots. Have you run it for a few days and checked that?
Leave your vents open. Those eggs need to breathe.
Finally, I hope your bator has a fan. Forced air bators should be run at 99.5 while still air bators should be run at 102*F measured at the top of the eggs.