I don't think 18 is some mystic magical number that makes a child an adult. Sure, in the eyes of many laws (and not even all of them) it does - but I don't think saying "When you're 18 we'll X" because what happens when she's 18 and she's not emotionally ready? I would, however, encourage you to encourage her to journal her
thoughts and feelings so that she can share them when the time ...