I liked how you wrote the story that we don't quite know much about, which is how Remus and Tonks actually died. The story flowed very smoothly, and I did like the afterlife scene with the reunion.
However, I did find the ending a bit cheesy. There just seemed to be too many "I love you"s being spewed out that it seemed to get a bit redundant as I kept reading.
But overall, it was well-written with good grammar and spelling. Nice work! :)