Considering what her body has gone through, there’s every likelihood that it has aged well beyond her chronological age.
Not everyone ages at the same rate and certain medications can accelerate that, like prednisone.
A liver transplant recepient must take immunosuppressent drugs for the rest of their live. This is to not reject the liver. So it does a number on their immune system. No wonder the 54 yr old was concerned for her healkth