Claire had this about six months ago. She was worried out of her mind for about 2-3 weeks inbetween the letter and the smear test, she spent ALL her spare time Googling it and finding out about stuff and ultimately it was nothing, she just had to have a slightly unpleasant (but brief) procedure to remove the cells and now she's fine.
You can pass on that anecdote to your friend if you think it will help.