To be fair I think she uses and is referred to as Carol during the entire film. In the sequel two characters use the name “Marvel”, one “Ms” and one “Captain”.

Of course it’s still surprising that you could watch a whole film and not be clear. In the first film there a very clear main character, and you know what film you’re watching, so that’s simple enough. In the second film one of the main characters fangirls over the character named “Captain Marvel”, so that’s straightforward.