I’m not sure about counting Aaron as one of the six. It seemed like Kate had claimed him as her own son. If Claire wasn’t one of the 6 then how could they say she had a baby on the island if she supposedly died in the crash? How long were they really gone? It seems like time runs differently on the island. Wouldn’t people assume he was conceived as well as born on the island? Who’s supposed to be his daddy?
When Jack was testifying on Kate's behalf he said that there were originally 8 survivors of the crash and two later died, so I guess that could possibly mean that Claire was one of the two who didn't survive, AFTER she had her baby.