Hopefully they do. Keeping her for longer seems like a good plan. Do you have any full body shots of the parents and her? That will put to rest if she's an ayam or a "traditional"
Adolescent feather quality isn't always excellent. They don't always take good care of their feathers. Is she an ayam/extreme? Those can have some difficulty getting to certain parts of their body and cleaning them. I wouldn't cull her from her breeding programme based on her current feather...