I prefer the [name]Katherine[/name] spelling. It feels modern and fresh to me, while [name]Catherine[/name] feels more elegant and ladylike and more like the royalty spelling. [name]Katharine[/name] is too Ms Hepburn and [name]Kathryn[/name] looks trendy. Plus I’d use the nn [name]Kate[/name]/[name]Katie[/name] and so spelling the full name with a K as well makes more sense to me.