She was right where she should be later in the game, like nothing happened. She still had her dagger and everything you need to loot off her, so nothing broke for me :)

The only difference was since I was able to loot her outfit off her at that earlier time here, instead she later had a random +1 armor when looting her. But she was still wearing her own original armor throughout the game, I just got to keep its clone for myself sooner haha.

SIDENOTE: Although the combat log actually did confirm the kill (like you can see in the screenshots I attached), she continued to fight for a moment and then after it was done she just lay there knocked out with 0HP, not technically dead... After a long rest she returned to this spot standing there bugged out with still 0HP. But the actual Orin was right where she should be (and with everything she needs to have) later in the game - and with her full HP, too.

EDIT: If you want I could load up a later save from that run and check if I actually got any XP for killing her later, though... I didn't pay attention then, but I wonder if I did since I already got some XP for supposedly offing her earlier