K.N.
I like the name. It is an older name, like something from my great grandmothers generation. Her name was Maude and her daughter was Zeona. So, there are some awful names too! Just think about kids in her class being able to say it. Leona should not be hard to say and I think people will like it. More importantly, do you like it? Can you stand saying all day long? It is very pretty and while not common, it would not be misspelled or mispronounced, and she would not have to be Leona K in her class, like when I was growing up, we had 3 Davids