George is closest in age to her and they're basically neighbors, so he's the most likely to know her. I like to think that any teasing she received from the twins (or at least from George) was good-natured in intent. He really doesn't want to make anyone feel bad when he makes jokes, promise.
Fleur would be quite up front with the thought "...You're exceptionally strange." But in what she hopes is a nice way?
Jessica, I dunno, probably has heard of the magazine and thinks it's a load of hooey, but wouldn't say so to the daughter of the editor. More like "...yes, that's nice, I'm going to go over here now." And then crack up laughing in private. Sorry.
Lily probably knows Xenophilius, if only by acquaintance, and I think she'd find Luna very sweet and if they ever spoke, would be quite interested to listen to Luna's thoughts on the world.