Born in Derry, Northern Ireland, McGuinness grew up singing harmonies with her mother and sisters in County Donegal.
McGuinness started running Oxmad Theatre Company, while working backstage on West End shows to fund herself.
In Edinburgh, she discovered a number of stand-up comedians including Ardal O'Hanlon (star of the hit Irish sitcom Father Ted) who made his UK debut at the venue.
McGuinness also premiered Eddie Izzard's first solo standup show where she received her prestigious Perrier Award nomination.
It was on the set of Molière that she met Laurence Olivier Award-winning English actress Noma Dumezweni, who would go on to become the focus of her 2015 short documentary, Noma (Forgiving Apartheid)[8] which premiered at the 2015 Foyle Film Festival[9] before officially entering the film festival circuit throughout 2016.
In Jake West's award-winning 2002 short, Whacked, she appeared as Niamh Ryan,[14] and wrote the theme song "Miss You", produced by Peter Cunnah of D Ream.
[16] The soundtrack was produced by Mickey Petralia and features the single, "Mama Can You See Me Now",[17] which was remixed by William Orbit and released later in the year.
[21] To transfer her skills across from theatre to film, McGuinness produced and directed a series of DVD extras including "Comedy Masterclass"[22] and "24 Hours Sexie".
Known for her combined passion for music and humour the documentary was reviewed by the LA Times as being a heartfelt documentary on comedian/actor Eddie Izzard which blends home movies, interviews and performance footage to fine effect to reveal a raw perspective on the creative mastermind.