Helena's birth father. Harold and Helena form a deep father-daughter connection when she returns to offer her help. At first, Harold didn't want her doing things before she proved helpful in the field.
Marie and Helena always had a strained relationship as she preferred to be held by Richard as a baby and little girl. Marie never told Helena that she wasn't Richard's daughter and even had her birth cerificate name Richard as her father. When she was trying with Richard and nothing happened, they saw a doctor who told them that Richard was infertile. Devasted that she may never be a mother, Marie went to her favourite brother-in-law for comfort. One thing led to another and they slept together which broke Richard's heart. Harold's family disowned him after finding out what happened but at Helena's birth, they forgave him except for Richard. Marie found away to introduce Helena to her real father when she was two years old, four and then six. After her death in an accident with Richard, Helena blocked out everything. Years later when Harold reveals he is her father, Helena develops a deep hatred towards Marie before accepting she was trying to do what was best for Helena.
On Helena's birth cerificate as her father but in actual fact, he is her paternal uncle. He vowed to raise Helena as his own but their relationship was strained as she went into her teens and became more like Harold in personality. It made him feel like he had failed as a father as she became like his brother, but with more confidence and charisma which came from his influence. After his death, Helena spent years blocking out the pain but after Harold revealed he was her father, Helena was forced to face the loss of the man who had raised her.
Helena stayed with one of her uncles shortly after the death of her parents before returning to college. She has regular contact with her uncles and grandparents.
Reese saves Helena from a bomb planted in her car but she passes out afterwards. As requested by Harold, John took her to him. Helena wakes up and Harold explains to her everything at first. She is confused but after it sinks in, she tries to leave but John blocks her way and Harold says that Helena is free to leave. Which she does. Sometime later, she saves John's life and offers to help them. At first, Harold is against the idea but John decides to give it a shot and she shows potential by hacking into a system that Root designed without having a bug implanted in her own laptop. John begins to develop a connection with Helena and called her by various nicknames whereas her father refers to her by her full name. John even trains Helena in hand to hand combat which she picks up with ease. During one session, John flips Helena and pretends to attack her, which she sweeps her leg under him, surprisingly as he thought she'd use her hands. She sits on him and claims to win but he flips her over to lay on her, before kissing her. Regretting it, he jumped up and left her confused. Afterwards, Helena shows cool indifference which makes Finch aware that something is going on.