After completing a journalism degree at the University of South Australia, she joined Central GTS/BKN in Port Pirie in 1997.[2]
In 1999, Mangiarelli joined the Australian Broadcasting Corporation.[2] She worked for the ABC in Tasmania, South Australia and Western Australia.[2]
In 2001, she anchored the ABC's Australia Television bulletins from Perth which were broadcast into the Asia-Pacific region.[2]
Mangiarelli joined the Seven Network in 2004.[2]
Following the departure of Leigh McClusky as host of the South Australian edition of Today Tonight, Mangiarelli was appointed as her replacement.[3]
Mangiarelli continued to host Today Tonight for 12 years until it was axed in 2019.[4][5]
In 2017, Mangiarelli was announced as the anchor of a new afternoon Seven News bulletin on Channel 7 which launched at 4pm on 31 July 2017.[6]
After Today Tonight was axed in 2019, Mangiarelli continued her role on the afternoon bulletin until that too was axed in 2020 and replaced with a bulletin from Melbourne.[7]
Following the axing of the afternoon bulletin, Mangiarelli moved to reading the weekend evening Seven News bulletins, replacing Jessica Adamson.[8]
In February 2021, Mangiarelli was paired up with Mike Smithson on the weekend bulletins as well as a new local 11:30am Seven News bulletin on weekdays.[9]
In September 2022, Mangiarelli was teamed up with former 10 News First sports presenter Will Goodings to read the weekend bulletins.[10]
Following the retirement of long-serving Seven News presenter Jane Doyle, it was announced Mangiarelli and Goodings would replace Doyle as weeknight presenters of Seven News in 2023.[1] On their first night together, 7NEWS Adelaide recorded more than double the ratings of rival Nine News Adelaide, with 132,000 viewers to the latter's 61,000.[11]
Apart from her roles with Seven News and Today Tonight, Mangiarelli has also been a part of the annual Carols by Candlelight telecasts and contributed to South Australian state election coverage.[12][13][14]
In 2016, she hosted a television special titled Finding the Beaumonts, which covered the 50th anniversary of the Beaumont children's disappearance in 1966.[15]