Overview
Ib is a 9-year-old girl. She has a cute outward appearance, with long brown hair and red eyes. While her name is pronounced as "Eve", it is written (and officially romanized) as Ib.
She comes to the art museum for the first time to see the "Guertena exhibition" with her parents, but after looking at a certain painting, she is suddenly whisked away to an alternate world within the art museum. The red rose she finds there symbolizes her life force, and she will die if all of the petals have scattered.
She wears a white blouse with a red scarf, a red skirt that ends just barely above her knees (the official site says it's because she's a little rich girl), blue-black knee-high socks, and red shoes decorated with bows of the same color. Her starting inventory holds only a lace handkerchief, which was a birthday present from her mother.
Personality
Ib is a silent protagonist. She never speaks a word in-game outside of dialogue choices, but it is also interesting to note that Ib rarely ever shows any expression (although she is not entirely emotionless).
She is described by fans to be a quiet and unusually mature girl. Due to an early scene where her mother first warns her to keep quiet in the museum and then notes that she probably does not have to worry about Ib causing trouble, this may actually be the case. (Of course, this could also indicate that she's just good at doing what she's told.)
Ib also does not outwardly express fear at anything she sees in the museum, and is thought to be strong of heart because of that.
She gets along well with her parents, and loves her mother very much.