I suppose that anyone who has gone over to look over the Winx Club profiles have noticed (or is freaking out at dear Stella Solaria) that Tecna's status is 'Princess.' I can explain this since it was I who told Stella Solaria to write this.
Tecna is a princess, pure and simple. This is revealed in the Winx Club comics, issue 25 Logic and Love, that are only published in Europe and only available to Canada in French (mainly, in Quebec I believe?). Luckily, you have this nice person here, winxcomics who scans the comics making them available for your viewing pleasure in North America. I would like to note now that the comic series came out first in Italy, and then the actually TV show. This is the equivalent of a manga coming out first and then having it made into a show (e.g. Naruto, Dragonball Z, One Piece, etc.). A more familiar example is the W.I.T.C.H. series; the comic came first and then the show.
This is her father:
This is her mother: (whom we only see in issue 30)
If you want to read the comics, here!