I have learnt what the spaces need to be in front of ? ! ; » and after « in French texts, namely thin spaces (1/8em). I got that from this question and its answers:
[Principles of Typography for different languages](https://graphicdesign.stackexchange.com/questions/13697/principles-of-typography-for-different-languages)

Now we also need to make sure that those thin spaces behave like non-breaking narrow space. There is a code point in Unicode for this purpose (U+202F) but it is 1/3 of a normal space (U+0020) and it is missing from many of our working typefaces.

So I wonder how this is done in France please. We are producing our documents in Scribus (very latest 1.5.3svn with the new text engine). But if there are French users who can share how they do this in InDesign it might help us, if we manage to adapt the work-flow to Scribus.

Edit: Sorry, seems my question was unclear: I am not asking about what lay people are doing but was talking to the main audience of "Graphic Design" here. We are interested to make our printed documents the same quality as contemporary professional output in France. We want a narrow space with punctuation and we want to avoid orphan-like punctuation at the beginning of a line. We know what we want; the question is how do designers produce those nice results in France? Does everybody write their own scripts? Are there some tools we have missed? :tidE

Do you use scripts? Do you have the 1/8em thin space on your keyboards? How to you guarantee that the punctuation glyphs do not jump to the next line? Do you get your fonts tweaked by the manufacturers? 

We are producing French texts for paper and for websites, but we are in West Africa, so we cannot just ask next door. Our budgets is also very limited, so please answer more than just "pay for an InDesign licence and activate option 4711". We cannot pay, but we would gladly investigate option 4711, if it does exist for that purpose. Thank you.

Update 2017\_06\_14: Since no user shared real-life experience from typesetting in France, I have ordered two books from France. There are still stuck/lost in the mail (I am working in Africa). I have not forgotten to mark a final answer but am waiting to see what the documents can add for an answer.