I think it would be a wonderful time for her to be able to travel with her elderly relative. She will gain a lot of confidence and knowledge and also have the pleasure of the older lady's company. She may not have too many opportunities to do this as her relative is elderly and the memories would be treasured There is nor reason to think that anything negative would happen, but measures could be put in place just in case. When children travel unaccompanied on aeroplanes etc. I know that the staff is on extra alert to be watchful so if anything untoward should happen to G grandma, your daughter only needs to approach the authorities with any information and she would be perfectly OK. I was 13 when I travelled independently and also with my Grandmother at other times, and that is only a couple of years older than your daughter is now. I only speak from my own experience but you best know the level of maturity of your own daughter and her ability to cope with the travel. All the best with your decision.