konceptual99 It wouldn't surprise me if she was never that regular even as a young person.
To get that good at tennis you have to devote an incredible amount of time to the sport, so you couldn't possibly be attending to all the usual Watchtower demands in full, or anywhere near. I would hasten to add neither could her parents, who would have had to have been very committed to helping them reach such a standard. Ferrying to practice, tournaments and the like.