How old is this child, and does she want her room painted red? And if she later decides she doesn't like it, how quickly could you paint it a more agreeable color?
Is there a reason you want to paint the room red?
Speaking only for myself, I wouldn't last long in a room painted that color. Maybe one accent wall would be fine, and the rest of the walls a less abrasive color.
When I was pregnant, I thought of painting my son's nursery orangey-red, so it would be more like the womb. That's pretty amusing to remember now. He probably would have taken one look and cried. That said, when I was 12, I had a room with gold walls (a pretty darn deep gold, too), red curtains, and a red rug. My long-suffering mother never said a word against it, and I LOVED it, though it probably looked a bit like a bordello. Deep maroon reds were popular in that recent decorating period when everyone was keen on their house looking like an English manor's library. I don't think I've read any research that says everyone is negatively affected by red paint on a wall, but I have seen lots of decorating articles that suggest a light hand when using a strong color. Maybe the color can be used on a bedspread or accents of other types (throw pillows) while something more neutral is used on the walls themselves.
I would like to know why you want to paint it red ,seems extreme may I ask why?