Leena , age 4 (approx.), was introduced during the first game in the Vandal Hearts series as a Biruni mage that lived in Frontier Village beyond the Torog Mountains. It is revealed soon after her introduction that she is in fact the past version of Eleni Dunbar prior to her adpotion by General Magnus Dunbar.
Leena, born in Frontier Village beyond the Torog Mountains, was raised presumably by just her grandfather, Orosius . He taught her the spells of the Biruni Mages, resulting in her becoming an advanced magic user for her age. When she was about four years old (assuming that Eleni, as stated in the offical guide, was 19 when she was introduced to the game) she had her first encounter with Ash and his companions when she was rescued by them after being attacked by monsters while picking healing herbs. Zohar commented on her ability to cast such an advanced spell for her age.
After her rescue, her grandfather reveals that he and the other members of the village, including Leena, were descendants of the ancient Biruni Empire, which made them Biruni Mages. She then accompanied Ash and his companions to Smoking Bones Cave where they had to prove Ash was worthy of having the seal of the Vandal Heart broken.
When they arrived back at her village, she found that Sabina of the Crimson Guard had burnt it down and killed her grandfather Orosius . He told Leena that she is the only one that can now break the seal of the Vandal Heart and that she must accompany Ash and his companions to do so. As a gift to console her, Eleni gave her the pendant she was found wearing by Magnus eighteen years prior. She told Leena to let it be a reminder of who she was and invited her to join their party once she broke the Vandal Heart's seal.
Before Leena was just about to break the seal, Xeno arrived and opened a time vortex, sending her fifteen years into the past. It was then that it was revealed she was in fact Eleni, and that she would be found by Magnus eighteen years in the past.
Orosius - As her parents did not feature in the game, it can be assumed that he, as her grandfather, is her primary care giver. He also taught her the spells of a Biruni Mage.
Eleni - Before Eleni knew that Leena was her past self, the two formed a close bond. Eleni treated her much like a younger sister. Their bond in game is evident where at Orome Lake , Eleni must be next to Leena at the temples entrance in order to acheive map victory.