Being an alicorn princess had been a tough job, but now in old age Twilight Sparkle has finally been able to retire. Her ascendant alicorn status didn't give her immortality like Celestia or Luna, but it did extend her lifespan significantly. Now all that meant was that she was the only one left.
Twilight is crippled and weak, but manages to return to the Ponyville cemetery. She just had to see them. One last time.