Logical place for it -- the heroine managed to expose her ignorance of why the inn is called the Princess's Rest, and the other character would explain it. . . .
Whereupon it dawns on me that the character who would boldly venture on the tale wouldn't tell it very well.
I can plausibly have another character finish it in a more detailed manner, but the question of how my main twosome learn exactly how the princess came to marry a crab in sufficient detail. Hmmm. the character who finished the tale intends to tell them that -- and the one about the ogre's feathers -- so they can tell the travelers who want to know. Especially since they can see the castle in question from the inn. . . but still there's the little bit of avoiding redundancy.