Amira gets a tracker that shows where Laetitia is.
It shows following coordinates: 48.8566 N, 2.2322 E
You can just google with those.
This is the low-spoiler guide for "Track Laetitia" puzzle in Chinatown Detective Agency. Unlike in normal walkthrough, you get gradual hints on how to solve the puzzle. Click the big button below to see your first hint. If the hint contains a spoiler, you will be warned about it before clicking.