Like I said, I'm at work, so I can't verify this; but I'm seeing on Twitter that Elma's 'likes' are seafood and art, and her 'loves' are Pipestraw Smoothies and the Codweave Safety Blanky.
ELMA LOVES HER BLANKY! I'M SCREAMING RIGHT NOW!
I can confirm the first two, but I'm not sure about the specific items. That aside, some of her voiced lines are as follows (roughly, since I'm doing this from memory):
"Not much worse than the barracks on Mira." (After resting at an inn)
"Watch out for Tyrants that come out at night. Ah, wait, you call them Unique Monsters, right?" (Nightfall)
"Makes me wish I had a probe to plant." (Discovering a new landmark)
Yeah, this has me a bit worried since those two replies, even though still vague, imply that she wasn't contacted for Smash.
I feel like that's reading too much into this. By themselves, these statements don't really mean anything, especially if you compare them to Pyra/Mythra's voice actress outright stating that she hasn't be contacted about anything Smash.
Edit:
I managed to reach the place where Elma's fifth conversation for her "Keen Eye" field skill takes place. It's essentially a continuation of the scene where she, Shulk and Rex all stand together by the Nopon archsage, except this time, KOS-MOS and Mythra are there, too. They're talking about how they all have a feeling that they've been brought together for a reason. Elma also has some thoughts about how her experiences in Alrest might help her uncover the mysteries of Mira, and Shulk reflects on Alvis' final words to him, which also erases any last doubts that Shulk and Fiora aren't pulled from their post-game.
Speaking of that, though - there doesn't really seem to be any hints of which point in time Elma comes from, but considering Shulk and Fiora, I'd wager that she's also from a point after the end of X' main story.