Hello,
I have been living and working in France for 3 years now, so I can give you a little idea about visa processes in France. Firstly regarding the validity of your visa, you will need to convert your student visa into 'work search(APS)' or 'work visa(Passport Talent)' depending on if you are looking for or already have a job(most likely) before your graduate respectively

. Your work visa stays valid for 4 years and is renewable! Your recruiter will need to provide some documents and a not so significant fee. However there is a lot of paperwork involved and french administration is known to be notoriously slow but is efficient!
Now regarding your spouse I am not very sure honestly, she might be able to work in France on an auto entrepreneur status but there are a lot of conditions involved. You should check the Campus France website for more information. For the rest of Europe I don't have much idea unfortunately. Also idk if it's worth mentioning but I am an Indian female who did a master's in France and visa requirements vary from country to country. But I am sure that you will have a wonderful time in France with your partner it's a beautiful country ❤️
Good luck !
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