Petunia cares for Harry

[dragon606]

I'm looking for a story where Petunia takes baby Harry to Gringotts shortly after Dumbledore dumps him. She accepts guardianship and her magic is unlocked. There is a house elf (Mitzy?), assorted compulsion spells, etc. Vernon doesn't survive. Petunia, the kids, and the elf move to France at the end. Any ideas? My search skills failed miserably.
If you know it was a Rough Trade story and you know who the author is, let me know. Thanks