A fanlisting is simply an online list of fans of a subject (in this case for Nino) that is created by an individual and open for fans from around the world to join.
There are no costs, and the only requirements to join a fanlisting are your name and country. Fanlistings do not have to be large sites (although some are), they are just a place where you can sign up with other fans. TheFanlistings.org is the original (but not official) web directory for fanlistings, dedicated to uniting the fans.
Description from TFL.

Nino is a young Anima Mage, raised by the Black Fangs: an organization founded by Brendan Reed, a sort of group similar to the company of Robin Hood, with the aim to give much wealtness to poor people, but which turned into a band of mercenaries ready to do anything for money and power and subjugated to the authority of Sonia, one of Nergal's Morphs.
Nino's real family was probably killed by Sonia, and we know for sure her parents were relatives of Canas (and of course Nimee and Hughes).
Nino is a cute girl (in appearences and personality), always optmistic, carying and naive. She can't read and for this reason people seems to be amazed by her abilities in magic (especially Erk). Anyway she's so skileld because she's able to sence the feelings of the spirits and she can somehow interact with them.
Even if Sonia despise her, she really loves her fake mother, peraphs because she wants, at all costs, to have a family (and that's why she's so affectionated to her brothers Lloyd and Linus).