A very helpful website for finding a doctor in Switzerland is the directory of the Swiss Medical Associaton (FMH). http://www.doctorfmh.ch/
The site is available in English, and you can search for doctors by specialization, location (canton, city or postcode), and languages spoken. There is no option to sort by gender, but the first name is generally a pretty reliable indicator. It looks as though there are 149 GPs who speak English in Basel, so hopefully you can find a female one close to you.
Good luck with your search!