Also, your logic is flawed and what I actually meant to post about but got distracted.
Stamford Hill is a largely orthodox community, as are the other areas you mentioned although yes, there are some liberal Jews. I would be hugely surprised if there are many, if any, Jewesses working as SPs in these areas because they will not want clients from their own background. (Note the number of SPs of colour who won't see men of colour). Also, haven't you read Portnoy's Complaint? Portnoy has a yen for shiksas, as do the majority of Jewish men I have known, so again, I would be hugely surprised if there were many, if any Jewish SPs working in those areas.
That's all.