u/wizardfingers suggested fixing teeth as a starting point ("the minimum"). And many other people have suggested the other things like weight loss, makeup, hair, etc.

The comment was being constructive and nice, and you butted in with a rude comment because they weren't harsh enough? Like I said, there's a difference between honesty and just being an asshole and bully. Point out the things she can do better, and don't make fun of her and say anyone who gives her a compliment has low standards. That's such a rude attitude, and it doesn't help anyone.