The problem isnt portraying women positively. Its portraying them accuratly. Most of my female cousins have been defined by their relationships with men. Moving from one unreliable guy and failed relationship to the next until they reach a maturity where they conclude 'screw men...time to fend for yourself'. Only then did they find they could 'go it alone'. The problem is they are wasting decades on the journey of discovery and not passing that to the next generation as anything but a 'learn it yourself' life lesson. Applying the hero's journey to women characters must ultimately deal with the shedding of their reliance on men as the 'giant penis' central to their universe.
Hope that is helpful in your own development of female characters.
Updated: Apparently it isnt.
The hero's journey is about shedding the current state of life in which you (male or female) are confined to a particular state. Not every individual ventures forth in search of change - some think the status quo to be fine thus never developing further. Of those who do, not everyone arrived at the same outcome.
Not every female PC/NPC rolls the wealthy merchant or Royal family as their weath and background. Most are going to begin at the bottom, dependant on or enslaved by Men, educational and/or economic limits. Shedding the status quo can mean ostracism by society (precisely why the evil sorceress is regarded as evil). If your female PC were subjected to public assault by the village priest and stoning by the mob for your character choices, is that PC going to risk change? Why risk change at all?