I don't hate the sister but it was so out of pocket saying that Maxi was never interested ...

So was the sister if I remember correctly

But it's true, maxi didn't have the mental capacity to see reality from other's pov.
Rosetta's words is a reflection of her not knowing Maxi enough, she probably saw maxi hating her, similar to how maxi had an inferiority complex to her sister venture of the abuses. especially ongoing the father would always use rosetta as model for a daughter when he beat up maxi.