[Bevdeforges]

It can depend on your exact situation, but I suppose the key issue is whether or not you have registered the marriage in France (i.e. have your livret de famille). If your husband was living in Brazil prior to the marriage, the question will come up as to whether or not he was registered with the consulate while residing there. Or if your relationship developed from a "long-distance" romance, other questions may come up, particularly how often you met before the wedding.

Don't go overboard on providing "proof" particularly if they are asking you for specific documents. When I had my immigration problems, we got attestations from friends swearing that we'd known each other for a few years before we got married, etc. Turned out what they were upset about was that I had no stamp in my passport showing when I had first arrived in France. (The rules were a bit different then - and in the process of changing, so I fell in between the "old" rules and the "new"rules.)
Cheers,
Bev

 

[Bevdeforges]

Their job is to be suspicious. Or they may have some experience of fake marriages either with Brazilians or other countries. It's pretty much impossible to tell "why" they challenge someone on a visa application. It's nothing personal (or at least keep repeating that to yourself as you go through all the requests for additional documents).
Cheers,
Bev