Does this mean Holly never got sick from Jonathan getting hit by the arrow?
Well, in part 3 everyone developed Stands relatively recently (compared to the start of the arc) because Dio only pulled himself out of a coffin, I thought? But obviously that never happened to Dio in this universe, and also it says on the first page that Jotaro was a Stand user from birth. So if it affected Holly at all maybe they resolved it long ago, or maybe--actually, post #2053272 says Holly has a Stand, too. In canon she had vines growing out of her back so maybe it's like Joseph's. In any case, she must have a hardier constitution here, even if she seemed pretty normal in the few frames she appeared in!
Lord Jonathan claims that this arrow gave him a Stand.Only OneSo it takes more than that to be a Stand User then.This is a special arrow crafted from meteorite. Countless others whom yearned for a Stand were stabbed by this arrow.Nearly all of them were said to have suffered a high fever for 50 days and died in agony. They died!?Even the unrivaled Ripple user Straizo was not enough.In addition, Master DIO became a Stand User when he resonated with our lord.He can see other people's Stands, yet he himself lacks the capabilities for a Stand. So far, the only Stand User born directly from that arrow is Lord Jonathan.