She may or may not be very vocal. She may or may not mount other does. She may or may not be very impatient or bossy with you. Then again you may have one like my Loretta and just never know.
generally they will be extra loud and advertise by tail flagging, especially if there is a billy nearby...but each individual animal is different and can show signs of heat at different stages of estrus...unless you are using AI and have to precisely indentify the heat stage, I wouldn't worry your billy will figure out when she is ready....conversely I watch the billy and can usually tell when does come into heat by their actions...upward curled lips, scenting their beards more than usual, slightly more aggression than usual, dirty looking front legs....You will know when you see them...providing you spend some time just observing your animals daily.