[3] From 2015 until 2023 she was a Trustee of the National Portrait Gallery,[4][5] latterly as deputy chair of the Trustee Board, and she chaired the project board[6] for the Inspiring People redevelopment which was completed on time for the gallery's reopening, after three years closure, in June 2023.

[9] Born Joanna Alicia Gore Ormsby, in London, Kennedy was educated at The Abbey School, Reading and Queen Anne's School, Caversham and won a scholarship to Lady Margaret Hall, University of Oxford; she was one of just three females among over a hundred engineering students and graduated with first class honours in Engineering Science and the ICE Prize.

[1] She was project director for redevelopments at the Southbank Centre designed by Richard Rogers, the National Maritime Museum Cornwall,[17] Hackney Empire, the Horniman Museum and she led the design team for the remodelled King's Cross St Pancras tube station.

[22][1] Kennedy's other appointments have included Vice-Chairman of the Port of London Authority,[23] a Commissioner of the Royal Commission for the Exhibition of 1851, a Trustee of the Science Museum[22] and a member of the Engineering Council.

[24] She was appointed to the Council of the University of Southampton from 1996 until 1999,[1] and to the Royal College of Art from 2001 until 2016 (also chairing the Buildings & Estates Committee).