I think the only different is spelling, they both can be said either way.
I prefer Clara, said kla-rah.
My PNLs = http://www.behindthename.com/pnl/37275
Top: Henry and Clara (main) / Sirius & Guinevere (GP) / James & Charlotte (top25)
Bottom: Delsin and Brisen (main) / Dinadan & Ninniane (GP) / Corvo & Deva (top25)
last updated 07/2021