[3] In August, at the age of 11, Maguire beat more than 800 competitors from 30 countries to become the winner of the under-12 World Golf Championship at Pinehurst in North Carolina.

In September, the twins were chosen to bring the Ryder Cup trophy to the stage during the presentation ceremony after Europe's win at the K Club against the USA.

On 21 May, Maguire was runner-up to her twin sister Leona in the Lancome Irish Ladies Close Championship at Westport, County Mayo.

On 19 July, the positions were reversed when Lisa triumphed over her sister 4 and 3 in the final of the Lancome Irish Girls Close Championship at Mullingar Golf Club.

As a result, both twins were picked for the European Junior Ryder Cup Team which later lost to the US at Olde Stone, Bowling Green, Kentucky on 17 September.

In December, she and her sister Leona were named jointly as the Women's Amateur of the Year at the AIB Irish Golf Writers' awards for 2008.

On 20 May, she defeated Mary Dowling of New Ross Golf Club by a 5&4 margin in the final of the Lancôme Irish Women's Close in Fota Island.

[4] She was chosen along with her sister Leona in the European side which earned a 12–12 draw against the US in the PING Junior Solheim Cup at Knightsbrook in Meath on 21 September.

On 7 July 2016 she was part of the Ulster team which won the 2016 Ladies Inter-provincial Championship for the second straight year at the Slieve Russell Golf Club in Ballyconnell, County Cavan.

At the LSU Tiger Golf Classic held at University Club in Baton Rouge, Louisiana, USA on 26 March, Maguire hit the first eagle of her college career.