Braids is not such a big problem. Once I spoke to a kenyan lady who works for Qatar Airways, and she said there are lots of girls who do it (not in a barber's shop, but at home).

Finding out who can do braids is easy, just ask (or better let your wife ask) someone with nicely done braids, who did it for them

The problem is that my wife wants to stop using braids and do hair relaxation, treatment etc. In other words a professional.