In March 2018, she partnered with Jacob Gallagher for a science project, and on their fourth study date, he introduced her to his step-father David Metcalfe and David's wife Tracy. A few days later, Leanna, Liam and Maya went to dinner with Jacob, David and Tracy which ended in disaster.
Leanna, Jacob and Gabby Thomas missed the bus for school, so the trio stole Ross Barton's car to get Gabby to her exam on time. The car ended up running out of petrol so the teens ditched the car. A few weeks later, Leanna and Jacob decided to cause trouble with Joe Tate by smashing up his car, instead deciding to take it for a joyride with Noah Dingle and Sarah Sugden.
In November 2019, Leanna and Jacob sleep together but she's heartbroken when he walks away afterwards like it's nothing despite having taken her virginity. Liam finds out and confronts him for treating Leanna like she's nothing. After Jacob insults Leanna, saying he wasn't that he only slept with her because she was nice to him but he'd never be into her. Later, Jacob's parents talked to him and he realised his behaviour wasn't okay and apologised to Leanna. She agreed to go back to being friends.