Need to know

Hi, my name's Aria Petrova and Yes! I am younger sister of Katerina Petrova. We used to be together all the time, but once the Mikaelsons showed up and we needed to hide!
Since that time I didn't saw my sister but I NEED TO KNOW where she is. I've heard of one curse that only blood of the witch and the vampire can break. That's why I need her!
But it won't be that easy Cause the Mikaelsons still looking for me!!