The thing is, you either have to accept that this is a name lots of people mispronounce or that is very similar to one pronounced differently, or you don't.
One of my dd's has such a name, and in a recent online poll, 50% pronounced it one way, 50% the other! So, however much I pronounce it one way, I have to accept that it gets pronounced the other way, a lot.
I still love the name, my dd still likes her name (though she does get fed up with everyone saying it 'wrong' before they hear it), and it's unusual.
My other dd has a much more common name and it's unambiguously pronounced, and of course it's easier, but then it's more common and some people don't like that!
Either make your peace with the mispronounciation which will continue, but you and her close friends and family will get it right, or change it now as it doesn't get better as the social circle/school expands and lots of people get it wrong!