Serena Blackfyre is an unseen character. She is not expected to appear in the series, being long dead by the time it begins.
Serena Blackfyre was wife of Daemon I Blackfyre, legitimized bastard son of King Aegon IV Targaryen and his cousin, Daena Targaryen. She was the mother of the twins Aegon and Aemon Blackfyre, and Daemon II Blackfyre.
Serena, along with her offspring, is mentioned in the House Targaryen entry of the book The Lineages and Histories of the Great Houses of the Seven Kingdoms.
|Daemon II Blackfyre|
"Maelys the Monstrous"
In the books
In the A Song of Ice and Fire novels, there's no mention of a Serena Blackfyre or the name of Daemon Blackfyre's wife. However, The World of Ice and Fire reveals Daemon was married to Rohanne of Tyrosh, a match that was arranged by his father, Aegon IV- and finalised by his half-brother, Daeron II.