Rebekah and Hope

The family relationship between the Original vampire, Rebekah Mikaelson and her niece, the tribrid, Hope Mikaelson. 
Rebekah is the paternal aunt of Hope, the daughter of Niklaus Mikaelson and Hayley Marshall. Hope's parentage and unique status as a living hybrid made her an ideal target for exploitation or sacrifice by numerous adversaries even before she was born. Rebekah, whose relationship with Klaus (or Nik as she calls him) had been strained for centuries, had left New Orleans not long before Hope was born to start a new life for herself. 
By the time Hope was born, the supernatural situation in the city had deteriorated to the point of all-out war between the Original Vampires, non-original vampires, witches, werewolves and mortal factions. Hope's parents along with Elijah, her paternal uncle, knew that she would be under constant threat from these enemies. Wanting a happy life for their daughter, Hayley and Klaus concluded that it would be best if she was not raised in the embattled city. The first step to achieving this goal was to convince the world that their newborn child had died on the day she was born. In order to ensure Hope's safety, Klaus then called upon Rebekah - who, despite their troubled history, he trusted above all others - to take and raise his daughter in secret, far away from those that would see her dead. She gladly did so, promising Klaus that Hope would be happy. 
In order to protect her niece, Rebekah carried one-fourth of the Hollow's spirit. She was unable to ever see Hope again, as doing so would put her in danger. However, as of The Kindness of Strangers, Hope has taken back each of the portions of the Dark Magic of the Hollow into herself, freeing the burden from her aunt, as well as her father and uncles, making it so that they can interact once again.