Kumik also has Chloe Moretz, Jessica Alba, Carrie-Ann Moss and Amanda Seyfried. Also a Pepper Potts. Super Duck has a Natalie Portman look-alike. Some bootleg Alice, Ada and Catwoman are in the market one time or another...
It's not like there's a dearth of female celebrity heads out there, it's just that they haven't made the ones you want. But I agree, they aren't as abundant as males (which is understandable too), and we like to see more.