I think this strategy is fine as well, as long as she is certain she would be happy to attend the safety (which seemingly would only happen after experiencing denials everywhere else.) And I think that’s hard for a HS senior to truly understand how those denials might feel and to not have a choice in the end. Obviously, some kids shake off denials more easily than others.
I’ve had plenty of students with IU Kelley as a safety (they meet the direct admit criteria and it was affordable) who had a similar strategy…apply IU Kelley and then a bunch of reaches. I did have one student who in the end was quite disappointed they only got into Kelley…that was partially ego though for sure. This student was denied at their flagship’s business school (a reach for all) and it hit them hard. So, the student appealed the denial in a long, drawn out process. And although I would love to take credit for the appeal being successful, I have no idea what happened there and wouldn’t advise anyone to repeat that strategy 
Student ended up attending their flagship.