"I've met the twins there a couple of times, actually," Luna said cheerfully. "They tend to ask the elves to help them with their pranks. They've always been nice to me. I like them. The Weasleys in generally are great. I talked to Ginny who's in my year a few times. She's great."
They entered the castle a short while later, then went downstairs into the kitchen. Luna knocked on the door, then went inside and they were immediately surrounded by a bunch of house elves, always eager to please and serve.
Coincidentally, they did have some apple pie, and soon they were sitting at a large table with not only apple pie in front of them, but also a large amount of other tasty treats. Luna sipped her Butterbeer and complimented one of the house elves on the exquisite pie.