My 15 year old has not started her periods yet. She is desperate for this to happen as all her friends have and she feels the odd one out. I have told her there is no rush and things will happen naturally when the time is right. But my mother has started pestering me saying there must be something wrong and I should take her to see a doctor. I don't feel this is something I need to do as she has only just turned 15 and think there is plenty of time yet. Am I being wrong, should I seek medical advice?