The more Elijah petted her the more calm Elena became. It was hard to fight such a pleasing thing and now she understood why cats liked to be petted and scratched so much. It was like little strokes of love all long her body.
Clearly Elijah couldn't understand her and Elena had no clue on what was going on. Was this a spell? Did Klaus do this? Elena didn't know.
The next thing to surprise her was that she started to purr loudly. It caused Elena to jump slightly because she hadn't expected her body to vibrate suddenly but there she was purring. And she couldn't seem to stop it.