Explanation:

1. Karaikkal Ammaiyar: She is one of the earliest and prominent female Nayanar saints who lived in the 6th century CE. She is highly venerated in Shaiva Siddhanta, a sub-tradition within Shaivism.
2. Mangayarkkarasiyar: She was a queen and is counted among the 63 Nayanar saints. She was instrumental in converting her husband, the Pandya king, and his minister to Shaivism.
3. Andal: She is not a Nayanar saint; she is actually one of the 12 Alvar saints who are revered in the Sri Vaishnavism tradition. Andal is known for her unwavering devotion to Lord Vishnu, not Shiva.
4. Isaignaniyar: She is also a Nayanar saint, revered in the Tamil Shaiva tradition.

So, Andal is the correct answer as she is not a woman Nayanar saint but an Alvar saint of the Vaishnavism tradition.