I’ve never heard of a [name]Charlotte[/name] being called [name]Carly[/name], so it doesn’t come naturally for me. But if that’s what you intend to call her 24/7, then you’ll be introducing her as [name]Carly[/name] and calling her [name]Carly[/name] and no one would know the difference unless they asked. And I’ve always thought of [name]Carly[/name] as a stand-alone name, so I would just assume (if I knew your daughter) that [name]Carly[/name] was her given name.
In summary, LOL, no, [name]Carly[/name] isn’t a “logical” nickname for [name]Charlotte[/name] (for me anyway) but that doesn’t mean you’d have to constantly explain it to people.
If [name]Carly[/name] is what you want to call her, then so be it! [name]IMO[/name] just b/c it’s not a “traditional” nn doesn’t mean that you can’t make it her nn. Some ppl have completely off nn from their real name and that’s ok. Like my name is [name]Raquel[/name], but my nn was [name]Rocky[/name]. Not exactly a direct nn, but close enough!
I love the name [name]Charlotte[/name], and when it comes to nicknames, I’m personally pretty liberal, so I don’t see a problem with using [name]Carly[/name].