Yea, I do hope that one day Nolan will make a great film with a lead female instead of a male. He was close to making one, called The Keys to the Street which had a female lead but the screenplay was terrible and I'm glad he never made it.

But I think a lot of movies, not just Nolan's movies, have more supporting male characters than females. Like Harry Potter for instance, we have Hermione and Ginny but the rest of the majority of sides and leads are male.