That's not true! Frodo saw her for the first time in the first part – that's where she actually appears for the first time.

But you shouldn't take words out of context. The point was that the relationship between Aragorn and Arwen wasn't specifically described until the third book. There were no conversations about a dog named Kashtanka and forcibly bathing the Nazgûl under the spell of "Long live fragrant soap and fluffy towels," that's what was meant. And Frodo, of course, saw her in Rivendell, but that's all.

Jackson's film is brilliant, IMHO.

Jackson's marketing is brilliant, and everything else is [censored].