Change spelling of DD's nickname

[newbian]

DD is 19 months old and has a lovely name that we tend to shorten. We've been spelling her nickname a certain way but DH and I are thinking we want to change it.

She has a unique name from our ethnicity so hard to get across but imagine Katherine nn Katie and changing to Katy.

Are we insane? If we do it do we like formally tell people or just start using it? When she starts nursery guess we'll give the new version.

Just start using it. You are overthinking this. People will still spell nicknames how they want. Your DD will probably change the spelling of it when she's a secondary school. I changed the spelling of my shortened name all the time as a teen. Even now I get all sorts of different spellings on cards etc. DS has a shortened name and people spell it differently in cards. I don't really care. I'm more worried that he understands it's not his 'official' name and that he spells that correctly.