The entries of Aegon III and Viserys II both name Visenya explicitly as their "only sister" ("This pregnancy led to the birth of Viserys' only sister, named Visenya." "This pregnancy led to the birth of the only sister Aegon would have, named Visenya"), but Baela and Rhaena could probably count as sisters as well. They are however not mentioned unlike the three Velaryons. Visenya could be the "only full-blood-sister" or "his mother's only daughter".