TGV Inoui / Train ZOU Train Tickets Different Name?

So I was supposed to travel with a friend to Paris. Nice - Lyon - Strasbourg - Colmar -Paris. We booked a bunch of train tickets already under our names (we're both males).

Now my friend cannot go, so I will be going with my mom instead. I read that the names are supposed to match, but also that they rarely check ID. The name on my friends ticket is obviously not even female.

Should I just use the tickets that we booked for my mom and I? Or should we book new tickets?

Should I be concerned about getting fined? How would they even go about tracking us down to pay the fine considering we're tourists from another country?