We bought Navigo Decouverte passes in 2018 (the purple version with the plastic shell.) I saw in a previous FAQ that the old passes can be recharged for up to 10 years. But I’ve since gotten married and have my maiden name on my pass. I assume the name should match my passport. Can I change the last name without buying a new pass?
On the Navigo Decouverte identity card, if the attached photo matches you and the pass has been properly reloaded with a week/day pass, you won't be asked for supplementary identification like your passport. So, your last name changing, shouldn't be an issue.
Perhaps you could carry an old piece of identification showing your maiden name if you were worried about the issue coming up?
Just as an aside, I've been controlled numerous times aboard trams and Metro cars / stations and have never been asked for supplementary identification (as the photo on the card matched my face). The controllers were only interested in that the Navigo pass had the correct subscription on it and I looked like the identifieid passholder.