So, I tried to use my upgrade certificates or miles for her, but they said it was not available. I thought when I called right after booking the tickets that the pnrs were linked....but I found out this cannot be done if the tickets are purchased separately. At least that is what the phone agent told me. I have now declined my upgrade and will ask at the gate if upgrades are available and if so either upgrade us both or neither. Plenty of seats open still.