It is almost impossible to make sure that the WG you see hasn't met a punter, who had been with other WG's, who in turn had been with other punter's, who might have been with a WG who may have done BB!
You can only go be instinct, reviews you have seen on here and any other reviews that you can find.
I like NW, it has happened to me, that a WG I used to see, has been with other punters that do BB. She doesn't, nor do I - but it is quite easy to make the connection, albeit tentatively, on some WG's.
Notwithstanding that WG's take BB off their profile and then re introduce at a later date!.
If you take all this on board, you would not punt!
For me - be careful of the new girls you see, be aware of the punts your regular WG's are seeing, but at all time do not take risks.