Now nearing 50, Higgins is a charismatic bundle of passion and rebellion. Her career has mostly been on the stage: oddly, her movie and TV credits are tiny. She says she is rarely asked to audition for either and doesn't care.
'TV is more about fake breasts and Celebrity Big Brother than drama, isn't it?' And in the theatre, too: 'Increasingly, people only want to cast a pretty face.'
Yet Higgins' commitment to her profession is absolute. Although she grew up in a Catholic family that frowned on theatre careers, she was determined the minute she saw Judi Dench in AWinter's Tale in the late 1970s. 'I wanted to be her,' she says.
'She was this extraordinary force and I thought: "This is what church should be like".'
Higgins' own life hadn't lacked drama: she left home at 17 and travelled for several years; she also gave up a child up for adoption. Now she is back in contact with her son, and admits the separation powerfully informs her understanding of Hecuba.
So how does she control her strong political opinions, her ideas about feminism and her instinctive feelings as a mother when playing a role so raw and so pertinent to our times?
'You have to be very careful always to serve the text and never indulge yourself,' she says cheerily. 'After all, it's no good to anyone if, half-way through the play, Clare Higgins starts to have a good cry.'
Hecuba opens tonight until Nov 13, Donmar Warehouse, 41 Earlham Street WC2, Mon to Sat 7.30pm (tonight 7pm), Thu and Sat mats 2.30pm, £15 to £29. Tel: 0870 060 6624. Tube: Covent Garden
