Ask the secretary of your Marie if they know of someone locally. And please go for a secretaire not a handholder, they will be likely to be more experienced with French admin.
Hello Sarah, may I suggest you remove your email and just ask people to PM you? This is a public forum and your email can now be seen by anyone in the world - which can lead to your getting spam. Just a thought.
You say you want a freelance translator but from your requirements what you actually seem to be looking for is somebody to research various administrative processes and advise you how to proceed. That is not really what translators do, they translate documents from one language into another language. It seems you want what is called a handholder but as JaneJones says, handholders are to be avoided if possible unless they come very well recommended, there are so many horror stories from people who have followed handholders’ advice and got into a mess because the advice was completely wrong for them.
You may get a mail shortly from a Carolyn. This is exactly what she does, so ignore any contrary comments. I / she knows exactly what you want even if you might not have expressed it as others might want to see it!
It isn’t entirely clear to me whether you need an interpreter, or a translator, or something of one and/or the other with some added functionality. It sounds very much like the latter.