User blog comment:Adventuretimegenghiskhan/How Old Is PB?/@comment-66.229.26.59-20110711141928

Princess bubble gum was 18 untill Mortal Recoil where she became 13, the same age as Finn. Follow this link for proof: http://adventuretimewithfinnandjake.wikia.com/wiki/Princess_Bubblegum