Although, her hair was dirty, you washed it. Anything harmful that may have been in her hair was washed away with the shampoo and water. Soap and water are one of the best germ killers. OT - I can't imagine being ill and not showering and thoroughly washing my hair. A nice, long, relaxing shower and hair wash is one of my get well celebration rituals. It feels so good to be clean after you've been ill. Of course, I think it always feels good to be clean and have clean hair. But to each his/her own.