Yep; sadly, you won’t be able to get upgraded. When MVPs are traveling with someone else, they can request to split the reservation to allow for upgrades, but that’s not an option when using a companion certificate. Even with two in the reservation, she should at least have access to the elite seats, so hopefully you can at least grab exit row seating. You’ll also get the two free checked bags benefit for both her and the child on the same reservation