Looking at the coins released by the mints (NZ Mint / Post, UK Royal Mint & Perth Mint) it is obvious the coins released to mark the birth of Princess Charlotte were all pre-designed as none of them bear her name or the word "Princess". The coins are all gender neutral. If not for the year and in the case of the Royal Mint coin which contains the words "second child", the same coins could be released for all the future children of the Duke & Duchess of Cambridge .... Staying away from these coins.
Naturally these coins have been designed prior to the birth and naming, that was only in the last few days but the process for designing a coin takes months at least. Not really sure why you'd create a thread just to tell people you're not interested in these coins...
With a mintage of 1000 only this sold out within hours of going on sale https://coins.nzpost.co.nz/2015/royal-baby-silver-proof-coin