Genital mutilation and sociological gender re-assignment are unfortunately not uncommon in parts of Africa, so I would be quite happy to believe that 'she' thinks 'she' is a 'she' but is biologically a 'he'. The mother's rebuttal quote of "she definitely grew up as a daughter" does nothing to assuage me of that possibility.
I think you'll find they have been careful in the words they use and sadly biology is not so clear cut and there are a few medical conditions which can result in an intersex state, most of whom end up morphologically female. Thats why the only refer to them as "Golfers"
All joking aside, they should have sorted this all out well before now, when she first entered national competition, let alone international.
She competed as a woman at the IAAF world junior championships last year. Has she butched up since then ? In which case there's drugs involved. Or did she have a similar appearance at the time ? In which case any testing should have been sorted out at the time.