#1 is backwards. Her face in the mirror should be in focus. People are hard wired from birth for facial recognition. Consequently backs of heads are much less than compelling.
#2 - Most f/1.8 lenses used at f/1.8 cannot focus sharply, and need to be stopped down at least 2 stops to be at the begining of that range of lens apertures that are tack sharp.
Two stops smaller lens aperture to get sharper focus is from f/1.8 to f/3.5.