In The Super Mario Galaxy Movie, Rosalina was revealed to be the older sister of Princess Peach. The canonicity of this movie to the actual games is extremely dubious, but despite that, a number of posts depicting the two of them have been tagged as sisters, most by @Evol_Lanrete, even those that have nothing to do with the movie, and some that were drawn well before the movie was even inceived.
I think it would be reasonable if Rosalina and Peach are tagged as sisters only if the work involves or mentions the movie, or if the work or the metadata implies that they are related. Before I write this into law in Rosalina's wiki page and clean up the posts, are there any arguments to the contrary?
