Norma-ler, or Once-lerxNorma, is the most popular opposite sex pairing in the Once-ler fandom.
In the 2012 movie, Norma is Ted Wiggin's grandmother, and is the one who told him about the Once-ler and how to get him to talk about what happened to the Truffula Valley, as well as buying marshmallows for him to give to the Once-ler.
Many people took this a bit further than canon showed, in fact some have come to believe that the Once-ler is Ted's grandfather. Norma knows some things about the Once-ler in the movie, thus triggering the idea that connections between the two may have been made offscreen and eventually leading to the conclusion of them having a love life in the past.
Many headcanons have been developed about this paring, fanfiction and fanart is also very common. However the two characters have no interaction or shared screentime within the movie itself, nor is a relationship between the two ever implied.