Now I don’t wish to be a pedant here but I think you’ll find it’s Esmè!
Yes, yes, whilst most people wishing for it to be pronounced Ez-may would use your (and most would argue the correct) spelling, wanting to be a little different Stacey (I would say and Joe but, well let’s face it, Joe wouldn’t really have had a look in on choosing the second coming/first female born in the world’s names) decided to spell it Esmè, so technically it should be pronounced Ez-meh!
Oh and when I say wanting to be a little different, well I suppose it could be that, but more than likely it’s ignorance or a typo however once you’ve made a mistake and plastered it all over both Instagram and official documentation, well you either gotta go with it or lose face and correct yourself, sucking up the backlash of your error. As we know all too well Stacey Solomon is never wrong and so Ez-meh it is!