Student or Learner
Celeste just smiled and said, ‘We’ll see’.
In American English (which is what I thought they used in the Philippines), those should be double quotes. In any English, the period (full stop) goes inside the quotes, because it belongs to the sentence inside them:
Celeste just smiled and said, "We’ll see."
"We'll see" is a complete sentence in quoted speech, and if it had been 'We'll see,' she said, the comma would go inside in both englishes. I want to believe you, but I think I would have remembered something so strange as a period belonging to a quoted sentence floating all alone out at the end like that.
No, I am saying that what is inside the quotes is a complete sentence, and the entire group of words is also a complete sentence. You can only have one mark at the end, and the stop inside the quotes belonging to the quoted sentence takes precedence.