"I create myself." Rose doesn't remember actually saying those words but she knows they belong to her all the same.
"I bring life." Another phrase that has come to haunt her over the centuries. She spoke them when she was a young girl in love, desperate to save the man who she believed and now knew was her soulmate in every sense of the word.
She didn't just bring Jack back forever but herself as well. Okay, so that part isn't entirely accurate. Apparently, Jack will die/does die/has died after somehow becoming the Face of Boe and well, she isn't entirely certain whether or not she can ever die. Rose has a feeling, and the TARDIS seems to agree, that they are tied to each other and both girls will either die together or continue on into eternity.
The Doctor has been gone for three hundred years. He finally reached his last regeneration and Rose held him as he took his final breath. "Read me to sleep," the Doctor had whispered and so she did just that. She never could refuse him anything.
She had hoped that somehow he would come back to her again but he never did wake up. Then she hoped that Bad Wolf had tied their lives together and that she would go with him but her heart kept beating, her breaths kept coming, and for a long time, so did her tears. Her tears come even now when she is still for too long and that is why she runs until she collapses these days.
Rose and the TARDIS grieved for years and both girls are still in mourning for the amazing, impossible man that they both loved but they do go on. They do it in the Doctor's name and in honor of him. They do it because they love the universe and want to protect what is good and right and lovely. They do it because pain and heartache have only succeeded in making them kind.
The TARDIS is never given coordinates anymore, everything is random. Rose trusts that they will always go exactly when and where they are needed. The two of them have never missed the mark.
Their legend grows. One more planet rescued from disaster, a civilization freed and left to rebuild, a war ended, a tyrant overthrown. Somehow Rose and the TARDIS manage to do what needs to be done. Always.
Every now and again they travel with a friend or two when Rose is desperate to hear a voice other than her own but it is always short term and almost never full time. The only person to live on the TARDIS anymore is Rose Tyler and while both girls prefer it that way neither objects to the occasional overnight guest.
It is morning ("No such thing as morning on the TARDIS, Rose Tyler.") and she is having her tea and toast in the kitchen when she feels a change, a shift. The TARDIS has found something that Rose needs to investigate. So she moves to the console room and begins piloting the ship so that she can see what has the TARDIS so worked up.
They materialize on a lush green hill overlooking an ocean. There is a village in the distance that would be charming if there wasn't currently an attacking army setting everything on fire and causing fear and panic among the populace. She pulls on her cardigan, makes certain that her sonic screwdriver and psychic paper are in her pockets, and heads out the door; making sure to lock it.
A young girl, fleeing the village is running in her direction but stops and stares in awe. "I've heard stories," she says, her voice soft yet rough from crying. "Are you the Doctor? The one who saves worlds?"
Rose looks at her, smiles softly "Yes, I suppose I am." She holds her hand out to the young girl, "Now, let's go see about saving your world."