I'm not a Chinese speaker myself, but even I can tell this is not quite what's going on.
For clarity, Mandarin is spoken, the written characters are simply Chinese. Characters have different pronunciations based on the Chinese language.
The full name in Chinese characters is 法兰西共和国, of which 法国 are the first and last characters.
Taking literal Google translations of these:
- 法 - Law
- 兰 - Orchid
- 西 - West
- 共 - Common
- 和 - and (conjugation)
- 国 - country
So we can already see that a literal translation of the characters is not really super helpful as it would be the Western Common Lawful Orchid Country? Of course we all know France is famed for Orchids??
Here is where things break down a bit, as the Mandarin pronunciation of these characters apparently is: "Fǎlánxī gònghéguó", which some users on Quora helpfully point out that "Fǎlánxī" is the transliteration of "France" in Mandarin. Coupled with taking just the first and last characters, you get "Fà-guó", which is a bit like calling the "United States of America" the "States" for brevity purposes. Each sound must have a character and that character may have a meaning itself. So, that these sounds happens to back translate into "Law Country" is more an accident of translation rather than France being famously law abiding.