Yes, too early. But if you happen to be near a school that has something of interest on campus – art museum, concert, etc. - it can be a good reason to check out that campus. Or just to drive through to see for the heck of it. But to consider for herself? Not yet!
It may help to equate taking your just finished 5th grader to look at high schools. She might think it’s cool to see the football stadium or science labs, but the criteria she’d likely apply to what would make her happy are almost certain to change.