Yes, as mentioned you log into your account and then pull up their reservation with their confirmation code and their last name. My Trips, Find another Trip.

The most likely case there will not be immediate upgrade space and they will be waitlisted. You will be informed of this at request time. Then they will be prioritized along with all other waitlisted travelers based on their status and then fare class, On popular travel dates, such a waitlist may never clear. You will not be able to see there placement until close to departure although a phone agent may release that inform, realize late bookers with higher status can jump ahead.