@fireheart:
I hadn't thought about it that way, that Minko is taking it out on the new girl the same way that Tohru tears her down, and that makes a lot of sense. As others have said, it wasn't so much that Ohana cooks better than her (she seemed to be enduring that), it's that Tohru made the snide comment about it. Same goes for what you said about her lack of support. She also lives in the inn like Ohana now does, so she may be just as on her own.
I wouldn't say that Ohana is going to smash the established hierarchy quickly (her battle axe of a grandmother), but she is certainly going to cut through the cold hostility and find herself a place at the ryokan. Perhaps she even make a budding friendship with her co-workers. Tomoe has already warmed up to her, Nako is just super timid and shy, and Minko can probably be tamed.
I can't say things have happened all that quickly. Even in a new job, it takes a bit before people feel comfortable enough with you as the new person before they start engaging you in their regular interactions. This is the only change Ohana is working on (aside from losing some her negativity and realizing her mother was wrong).