Mm... that's similar to what Hinata told me, once. When you think of a happy memory, or an important person... smiles can come naturally.

[She frowns again, though, glancing at the other girl and shaking her head.]

There must be a trick to being able to show a smile to try to comfort someone, though. When things are not going so well, but you must still try to smile to make them feel better...

[When she says "them," she may or may not mean one person in particular. A certain one-eyed blond asshole, perhaps.]