Rose is a cat +Anima, who grows long, cat-like nails and even hands smiliar to cat paws. She also gains agailty and speed, like most felines.
She is 16 years, which she claims makes her an "adult". She is a peddler, usually on her own, and sells jewelry she designs and makes herself. She met the group while she was traveling with an older woman called Margot, and all six crossed the mountains together.
She is very independent and kind, and also stubborn. Rose seems to disapprove of people often (like when the group needed money and Cooro asked for more pay for their services at the hotel), and gets mad at anything she considers unfair.
Rose has a younger brother called Pinion. She likes Senri because he reminds her very much of her little brother. Pinion was left with her aunt and uncle, but taken by the government to use his gift of being able to see anything once, then draw it (for maps and the like). She tried to get him back, and was foiled. Later on in that same manga, Pinion is returned to her, and she leaves the four main characters and takes her brother peddling with her.

Related manga:

+Anima Manga, 1999