I also have a small head and went through several mask before finding success with a mask from Fisher Paykel…the Evora full face mask. The Evora has an additional point on the top that gives another point of adjustment. Previous mask needed to be tightened trying to get them to fit. I am able to leave the Evora mask much looser and still have almost zero leaks because of the additional point of adjustment. I tried the ResMed “for her” masks, but they did not give me as good of a seal.
Good luck on finding a mask that fits.