[name]Do[/name] you think it’s realistic that a girl named [name]Josephine[/name] could avoid being called [name]Josie[/name] (assuming she wants that)? Does anyone have a non-intuitive nickname for themselves or their children and, if so, how does it play out?
[name]Just[/name] tell people she goes by her full name, I wouldnt worry about it, a polite person would respect that and call your child what you or them asks.
I don’t have a NN, some of my really close friends call me by the first syllable of my name but no one has ever really shortened it. My brother does not have one either and he has a very obvious one. At first he told everyone that he preferred his full name and now everyone is used to it and do not question. So I don’t think it would be a big problem especially after everyone gets used to the idea. Personally I cannot stand [name]Josie[/name] either, my favorite NN for [name]Josephine[/name] is [name]Effie[/name] but that could just be the Greek girl in me 
i think this is something that you can only control to a certain point and if you hate the obvious nickname it could be a good enough reason to pick another name. however, if you love [name]Josephine[/name] and at home she’s just [name]Josephine[/name] and you can handle her potentially being [name]Jo[/name] or [name]Josie[/name] at school than you should go for it.
I think it can, if you’re polite when you say “Actually, we prefer just [name]Josephine[/name]” or what have you. If you’re rude about it, people might do it just to spite you. However, if it would really bother you if someone called her [name]Josie[/name], or if when she’s old enough that she wants to go by [name]Josie[/name], then maybe you should consider another name.
Looking at from another perspective, what if the child hates [name]Josephine[/name] and perfers to be called [name]Josie[/name]?
If the question is can, then yes, definitely. If the question is will, there is no way to be certain.