The pronunciation key is not quite right. The English pronunciation (in England, the place in the English-speaking world where the name is actually used) is Jor-Jane-Ah. [noted -ed]
I hear British people pronounce this name "George-ain-uh". I have also heard it pronounced "Georgi-anna" as well. (Which I personally think sounds better.)
John Keats revised a poem he'd written as a very young man which he'd addressed to "dearest Emma", and replaced this with "Georgiana". So it must have four syllables, with stresses on the first and third, otherwise the metre doesn't work out. And Keats would not have made that kind of mistake.