My wife likes to shower every day when camping but doesn't wash her hair every day. As we dry camp almost exclusively, before the inverter, I had to drag the genny out each time we used the hair dryer and with other AC loads. Now with the 2000w inverter, life is easy but We still try to be carefull with our power consumption.
One thing that helps is a hair dryer that has 2 settings which are 1200w high, 800w low which is below most domestic hair dryers. On the low setting, the hair still gets dry but there is less strain on the inverter especially if the batteries are near 50% or there are other smaller loads on the inverter at the same time.
Or you could just ask her to stick her head out the window when under way after her shower if you don,t value your life.
Dave