Crescent Tides is not Luna's biological child- But rather adopted. She is aware of this and she does not mind- As she does not remember her original parents were either way.
She has a form of minor memory loss- forgetting minor things like objects or names. However she is known for being quiet and reserved, the only pony knowing a lot about her being her mother and aunt. Crescent also is able to see things before they happen through her singular blind eye, though the origins of this ability is unknown, it is theorized by many that she had gained a bit of Alicorn Magic from simply being around them since birth. Luna is also quite protective of her- And the two barely are seen apart.