John Westbrooke on an exhibition that focuses on one of the Bloomsbury Group

Vanessa Bell was nearly buried by Bloomsbury. The group of free-thinking artists and writers, based in London’s Bloomsbury and Charleston farm in Sussex a century ago, has always held an odd fascination, partly because of their complicated love lives; the New York wit Dorothy Parker said that they lived in squares, painted in circles and loved in triangles.

The novels of Bell’s sister Virginia Woolf and the economic theories of Maynard Keynes are still widely read; but what did Bell herself do, exactly? The new retrospective exhibition at the Dulwich Picture Gallery sets out to remind the world that she too was a painter.

She and Virginia grew up in a typically paternalistic Victorian family: Vanessa was allowed to go to art school, but only as long as she was home in time to pour her father’s afternoon tea. Still, she studied properly at the Slade and the Royal Academy under the likes of John Singer Sargent.

Freedom came with the death of her father, and with the exhibition of Post-Impressionists organised in 1910 by Roger Fry, the first to bring the work of Gauguin and Matisse to the attention of the British public.

The British weren’t impressed, but you can see the new influence on Bell’s work from the first room, in which visitors are greeted by a big portrait of socialite Iris Tree – plainly not a literal depiction but an attempt to portray a larger-than life socialite (she later appeared as herself in Fellini’s film La Dolce Vita).

To either side are portraits of people, also not naturalistic, about whom Bell clearly had more mixed feelings, as they both look as if they were moulded in jelly: Mary Hutchinson, her husband’s lover, and David Garnett, the lover of Bell’s own lover.

She experimented with cubism and pure abstraction (and wasn’t afraid to jettison modernist theory in order to paint some oranges and lemons just because she thought they were beautiful), but mostly settled on a sort of heightened representational approach, with figures standing out against broad flat areas of paint. Landscape with Haystack, Asheham is a Monet subject treated in Cézanne style, as solid-looking as Mont Ste-Victoire.

In The Other Room, a woman relaxes languidly on a sofa while behind her two others stand apart and look out the window. Studland Beach shows a woman and child tucked into one corner of the canvas while another on the other side is silhouetted against a tent. The caption notes: “It is tempting to read this picture as an involuntary expression of Bell’s loneliness during this period (her husband and sister were entertaining a dangerous flirtation at this time) or as a wider comment on modern womanhood…”

As that quote suggests, the curators have had a trickier time separating out the artist from the social being, and ignoring the gossipy tabloid stuff, than they evidently hoped to. The works of Keynes and Woolf are less likely to be analysed in terms of the emotional turmoil the writers may have been going through.

Bell herself didn’t separate her art out from her life. By all accounts she was the organiser at Charleston, central to the group dynamic. (There’s even a photo of her cutting a guest’s hair.)

In painting, she certainly wasn’t just a dabbler: she travelled to the continent, she met Picasso, she exhibited alongside Matisse. And yet for all she took art seriously, it sounds as if she sometimes sidelined it just as much as when she broke off to make her father’s tea. Tellingly, one of her paintings exhibited here had to be rescued from the rabbit hutch, where it was acting as a lid. The curators see this as a sign of her lack of self-importance, but it also hints that she just wasn’t always that bothered.

Legend has it that London gallery assistants, confronted with a previously unknown painting, would sardonically attribute it to the obscure Dutch artist Van Esserbel, because who would know? An early English modernist, intelligent, innovative and talented, shouldn’t be so obscure. And yet after going through this exhibition – which also includes an avant-garde range of household textiles she designed for Omega Workshops – I’m still not sure I’d recognise a Vanessa Bell if I saw one for the first time.

Sargeant had wondered if her colours were too dull; after her exposure to French modernism she brightened up considerably, for a while. And yet here’s Interior with a Table from 1921, furniture, a window and a green and pleasant view beyond … which looks much like Sussex but is actually meant to be St Tropez. When you think how dramatically the southern light changed Van Gogh’s vision, it’s strange that Bell seems hardly to have noticed.

After a bravura last room, “pictures of women”, the exhibition winds down, still in the 1910s (Bell died in 1961). Only The Other Room, from the late 1930s, shows her doing any outstanding work after the Great War. It’s a downbeat ending to what looked as if it was going to be a stellar career; but there’s enough on show to make you regret the work she didn’t go on to do.

Vanessa Bell (1879 – 1961) runs until 4 June 2017 at the Dulwich Picture Gallery. Tickets £14 (including voluntary donation), £13 for seniors.

www.dulwichpicturegallery.org.uk/whats-on/exhibitions/2017/february/vanessa-bell-1879-1961