But, there was nothing to be gained by dwelling on the past and the "what-ifs'. She could dream about how life would have been different, but she couldn't say for certain that she would've been correct. Given a time turner and the ability to change the past, she wouldn't have gone back to change her relationship with her husband. She would've gone back to when Albus Dumbledore was still alive and uncursed to tell him the locations of the horcruxes. Maybe that could've made the difference. Or everything would have happened exactly as it had.