A possible doctor who episode starring the 10th doctor David Tennant & american actress Lucy Hale as my own Charmed fanfiction character Melissa Hale.

The doctor meets an 18 year old girl with a mysterious secret. She was born
half white-lighter half witch but she & her cousins a witch & half demon/witch were adopted at birth after their parents Prue, Phoebe & Piper Halliwell plus Andy Trudeau & Leo Wyatt were all killed by the new Source who then tried to destroy the babies because of a prophecy an Oracle had about them vanquishing him in their later life but were saved by Cole Turner & the english equivilent of male "Charmed Ones" who then stripped their powers & gave to the Elders for safe keeping until such time they needed them which happened when their adopted parents were murdered in the future & the cousins found out about one another & moved into "Halliwell Manor" & became witches.

The meeting happens a little after Mel's received her powers which she can orb & freeze things in when they attempt to vanquish a time travelling demon.

The doctor doesn't recognise her at first until Mel tells him about herself which rejogs his memory of knowing how she goes back to the past years later to help "The Charmed Ones" vanquish the previous Source but Prue & Phoebe die before that happens & Mel becomes "Charmed" inheriting Phoebe's powers which she swapped with her's & she 'n' Piper meet Paige & become the new "Charmed Ones".

He doesn't let anything on about that but Mel senses he knows something though. They become friends at the end with a hint of her maybe been his companion but that doesn't happen