User blog comment:The Dragon Demands/The History of House Targaryen. Part IV: The Dance of the Dragons/@comment-5014364-20131202202530

Nettles didn't look like a Targaryen: she had brown hair and eyes. This has led to debates that she wasn't really a Targaryen bastard, and that dragonriding doesn't require Targaryen blood.

The other side of that argument is....there have been *numerous* instances when Targaryen children didn't inherit Valyrian features of white hair/purple eyes, because their Targaryen parent married a non-Valyrian. Bittersteel, for example. Nettles was apparently from Dragonstone or thereabouts, and could have been the bastard grandaughter or great-granddaughter of a Taragaryen. No one kept exact records of unacknowledged bastards....that's why they're unacknowledged bastards. No one knows exactly how Nettles related to the main line, or really how any of the other Dragonseeds did.