Interesting. Makes me wonder then about the eyewitnesses that claim they saw the father put the girl on the railing-this report would seem to indicate he wasn't even near the girl when she fell. I also don't recall seeing mention of a porthole before now (but it's been a bit hard to keep up, lol).
If it was the porthole area at the front of the ship, yes, it can get windy there. But, as you noted, wind alone wouldn't be enough to cause someone to go overboard. If someone was climbing/sitting on a railing, then maybe yes.
I still question this passenger that's sharing all these things the cast member told her. First, a CM told her they saw the girl climbing on the railing near the shuffleboards (but apparently the CM did not intervene when she saw the girl climbing?). Now, a CM (unclear if the same one or a different one) is telling her about wind and sudden gusts. It just seems like there's a lot of speculation here and some of it seems to contradict.