my 10 year old daughter is the same. She takes forever to get ready even if we are just popping to the corner shop as she thinks if she doesnt look good people will laugh at her. She hates the thought of people not liking her and if in a room with othe people will be convinced they are laughing at her etc.
These are indications of anxiety - common to generalized anxiety disorder. How old is your daughter and does anyone suffer from this disorder on either side of the family?