Her storylines focused on her relationships, including her lesbian fling with Nicole Miller (Sally Martin) and the most notable being her love triangle with characters Boyd Rolleston (Sam Bunkall) and Drew McCaskill (Ben Barrington).

[3] Originally commuting between Dunedin and Auckland for filming,[4] Vandervis struggled with the extension due to personal relationship issues and considered quitting the show.

"[7] Harper arrived at Shortland Street shortly after returning from a mysterious past in New York, supposedly to visit best friend Sarah (Amanda Billing).

Taking on more responsibility at the hospital through management positions, Harper moved in with Drew and they become legal guardians to her distant cousin Ashley (Ruby Lyon) until she died from hitting her head in a teenage brawl.

Reconciling some months later, Harper fell pregnant again and opted to keep the baby; giving birth to an inter-sex child, Billy (Arlo Jackson) in mid 2018.

Spending some time overseas, the hospital colleagues noticed a change in attitude from Harper when she returned and when she broke up with Drew for kindly donating his liver, she was diagnosed with a brain tumour.

Growing close to a young car crash survivor Marley Fraser (James Allan), Harper and Drew fostered the boy and began a long-running clash with his biological mother Talia (Lydia Buckley) who attempted to take him back despite her criminal history and drug addiction.

[9] In 2022, Harper fell pregnant again, giving birth to a daughter Skye McWhitley (Isabella Stillwell) and after suffering with Postpartum depression, fled Ferndale and her family.

Aiding Drew in holding Owen hostage, the two were later framed for his murder but proven innocent with the help of Harper's estranged mother Olivia (Alison Bruce).

The affair lasted for several months, with Drew soon uncovering the truth and ending the marriage - ultimately attempting suicide with Harper helping nurse him through recovery.