User blog comment:Luffayking12/Luffy vs. Doflamingo/@comment-5144035-20111016225656

Shirahoshi joining is alot more plausible than you think, like Rici said. She's had a bad past, a unique personality, and we have no idea how strong she is in battle yet, so don't go making assumptions so soon. Also, Ivankov has no part in the arc, so there's no way he could join. Also, another thing to add is that Oda said the next crew member was going to be a female.