Jenni was born in Elgin and brought up in St Andrews, she returned to the north east to study accountancy at Aberdeen University and then qualified as a Chartered Accountant. Following this she moved to Glasgow to work at BBC Scotland working in many different programme areas over 18 years including helping to establish BBC Alba.
Jenni has since moved to Islay, where she volunteered for charities including the Islay Energy Trust, playing a key role in establishing a community wind turbine on the island; and worked as manager of the Museum of Islay Life. Jenni chaired WW1 commemorations on Islay in 2018, which included over 40 events involving all elements of the community.
As MSP for Argyll and Bute, Jenni has contributed to three parliamentary committees and held membership on 15 cross party groups. Her campaign for the removal of VAT from defibrillators received cross-party support in the Scottish Parliament.