Make Leona able to proc her passive for 50% damage and 100% to Jungle monsters.
She fits what would make a good top laner more than a support since shes one of the supports that appreciates having gold to have a impact, also a lot of her kit just feels really strong for a solo lane as well as tport ganks over sitting in a bush waiting to e someone when she can have a lot more "interactiveness" in a top lane with different trading combos.
Not to mention she would be balanced there since she doesn't have any unfair laning prowess and frankly she should have been a viable top laner from release and a simple passive proc by herself would single handedly be capable of making her more flexible in other roles.
She also would be a considerable tank jungler since she excels in ganking and having early pressure and tower diving while also not clearing the jungle at a non existent clear speed so she would be relevant.
Just would be a simple change to promote "champion diversity" which is what riots goal this season was and would definitely be a easy way of helping that goal be achieved.