You might start first by defining exactly what you are researching...
Are you looking for any female with a Commercial Pilot Certificate (that's what they're called in the USA, although certificates are commonly referred to as licenses)?
Or do you want to find females who are working as Commercial pilots?
Or just ladies who are flying for the majors?
How about a woman who has an ATP? Would you consider her a "Commercial" pilot or an "Airline Transport Pilot"?
Try Landings.com or call AOPA.