It was more than a simple question about the shirt and a quick answer. It was a conversation, and she said she was from the Philippines. More than once. Thailand was not mentioned. I did ask follow-up questions to clarify we were talking about her origins at that point and not her shirt, and that was her answer. I have no reason to make this up; it's just what happened.
For the record, she is pleasant and I will see her again, regardless.