Let's rewind a bit
The impact of the explosion kept Veronica down for quite a while. After she woke up she looked around her dark surroundings despite the sun being up since the blinds were closed to this place. She decided to leave and took away her car back to her apartment.
When she was back she was delighted to find the apartment still empty. She took a shower changed herself and stared at the mirror with a curious gaze. "Looks like I finally got you…" she smiled, which seemed genuine but rare on her face "...my big twin sister".
That moment few ghosts who were supposed to be not visible by Veronica came there. When they looked at Veronica their eyes widened for a moment. You see, with her only around it was hard to tell for them if it was Veronica alone, or was she possessed by Chloe.
She smiled at them before she declared, "It's Chloe". They smiled at that before Ken spoke up, "You finally managed to possess your sister"!
"I...did not" she said awkwardly.