Turn back time

Veronica Granger is the adopted sister of Hermione Granger no one knows where she came from or who left her she just showed up on the Grangers door step on her 3rd birthday.
That being said she was a witch. Two years older than Hermione, Harry and Ronald.
So when Dumbledore comes to collect her for Hogwarts she's in awe and confusion. She's sorted into Gryffindor with her new friends Fred and George Weasley whom she met on the train after they pulled a prank on Marcus Flint a Slytherin who had made fun of Veronica.
However when in her 6th year she's selected for the Tri wizard tournament making her the 5th champion that year.
In the last task when touching the cup she is sent back in the future where she meets Lily Evans James Potter Sirius Black Remus Lupin and Peter Petegrew in their prime.
When it was time to leave she's stuck between going back to her ever changing world or staying and changing things along the way. Most importantly Sirius Black