The Prime of Miss Jean Brodie/ The Girls of Slender Means, Assembly venues, Edinburgh

Muriel Spark wrote of her most enduring creation, Miss Jean Brodie, that she was "an Edinburgh festival all on her own": vibrant, bursting with culture and a touch overwhelming, you might infer. This year, it is Spark herself who is a festival all on her own with two large-scale theatre adaptations of her novels and a book festival event dedicated to a new doorstop biography of the Edinburgh author by Martin Stannard.

In many ways, Spark's novels – tightly written, with their girlish ensembles and fragrant sense of place (Jean Brodie set in the rigorous corridors of the Marcia Blaine School in Edinburgh, Girls in the May of Teck women's hostel in London) are made for the stage.

Laurie Sansom's elegant production of Jean Brodie, which started life at Northampton's Royal & Derngate last year, feels entirely at home in the echoey, dusty, creaky Assembly Halls. The place reeks of old-school spirit even before the gauze is lifted on Neil Irish's lovely set and rows of immaculately trained singing schoolgirls in plaits and pleats.

The rise and fall of Miss Brodie, a progressive teacher trapped in a conservative school, seeking to mould her chosen few with her "stimulating" dress sense and unconventional teaching methods has been adapted faithfully by Jay Presson Allan. And if she doesn't quite snuff out the memory of Maggie Smith's querulous addresses to her "gels" on film, Anna Francolini – willowy yet with ramrod back, generously inspirational yet selfishly manipulative – brings fresh pertness and wittiness to the lead. Her run-ins with the frowsy, brogue-wearing Miss Mackay (Lesley Nicol) are a joy to watch and her favoured pupils are played with great maturity by a quartet of talented young actresses. Vastly enjoyable.

Girls is a more impressionistic affair from the Stellar Quines company, weaving a dream-like vision of Forties London through a group of resourceful young ladies, all keeping their peckers up, digging for victory, reciting edifying verses and sharing a single, gorgeous Schiaparelli silk dress between them for nights on the razzle. Set in 1945, between VE and VJ Day, Muriel Romanes' production makes clever – if initially confusing – use of moving screens and bellowing telephones to evoke the dolls'-house nature of the set-up where owlish, jolly-hockey-sticks gals, lissom models and good-time girls live on top of one another. Somewhere along the way, though, Spark's story gets a little lost. In producing a show of some style, Stellar Quines lose some of the novel's fine substance.

To 31 August (0131-623 3030)