Rose Tyler
Rose Tyler was a human young woman and a companion of the Doctor. In at least two universes, she ended up falling in love with the Doctor only to be separated from him, ending up trapped in a parallel world relative to their original one where the Doctor remained.
Biography
Reunited with the Doctor
One universe's Rose originally acted as a companion to her universe's Doctor. The two lived through a “Bad Wolf” incident that left Rose unable to ever age, although neither of them realised this side-effect until many years on. Eventually, she was trapped in a parallel dimension they nicknamed Pete's World, where she lived happily at first, only to outlive all her friends and family and grow bitter.
Finally, one day, Jenny Everywhere turned up on Rose's doorstep and offered to take her back to her home universe to resume her travels with the Doctor, cryptically saying that it would be “better for everyone” if the two were to be together again. Rose naturally accepted and Jenny shifted her directly into the control room of the TARDIS, where she recognised the woman at the controls as the Doctor thanks to the age in her “brilliant” hazel eyes and her eccentric clothing. After Jenny left, they headed to the TARDIS's library to catch up. (PROSE: Shifting)
Behind the scenes
Rose Tyler was the main companion of the first two seasons of the 2005 revival of Doctor Who. Her only known appearance in Jenny Everywhere media has been in Shifting, an avowed fanfiction; it was thus unlicensed, and, moreover, an explicit “Alternate Universe” relative to the “canonical” Doctor Who universe.