The Wainwrights are, let’s face it, not a family who have been without publicity in recent years. If it isn’t the worldwide adoration granted to Rufus, it’s a tour from Loudon or a new Christmas album from Kate and Anna McGarrigle, Martha and Rufus’s mother and aunt respectively. Do we really need another article about any of them?

We surely do, as this clan continue to write new chapters in their lives, and such is their level of talent (and drama) that they demand attention. This year has so far belonged to Rufus: a new album, tour, and his Judy Garland shows. Now, it seems, it is Martha’s turn for the spotlight again. With an upcoming UK tour and a new album set for release early next year, Wainwright the younger is emerging once more.

It does seem though, that we are still feeling the aftershocks of her eponymous debut album, released in 2005. That album was a cutting, often brutal adventure into her own heartbreak (‘Don’t Forget’) and deep resentment at her father’s habit of voicing his reservations about his young family in song when Martha was a child (‘Bloody Mother Fucking Asshole’). Despite the lovely melodies and the infectious energy, her debut is a draining, painful listen.

“It was certainly cathartic to make and release it,” she told londontourdates. “Sure, a lot of pain. I think because I am fundamentally happy, it’s easy to write songs about the times I am in pain. It is not hard for me to ‘go there’. I like crying while playing and thinking hard about my sad feelings about something. “The new album is a little less about me and hopefully more about the world around me.”

Pain is something she is no stranger to, both in her personal life and in her quest to have her music taken seriously, not least by herself. Her journey as a singer-songwriter has been fraught with doubts about her ability. This was not helped by one occasion, the story often told, of when she and Rufus were supporting the Barenaked Ladies at a stadium gig. After the ‘jock’ sorts in the audience had shouted things like ‘faggot’ at Rufus, Martha stepped up to the mic to sing in French, only for a stadium-ful of fans to laugh at her. Rufus is reported to have said: “This is my sister Martha, and she has more balls than all of you combined.”

She undoubtedly has balls, but is still often daunted by the prospect of writing her own material. Despite this lack of confidence, she has found some important admirers. Seminal 60s producer Joe Boyd named Martha last year as one of the few contemporary artists who excite him, though he expressed reservations at the production on her album.

“Joe’s probably a bit bitter I didn’t ask him to produce the album,” she joked, “but I also think he’s right in some ways.” Even more impressive, Bob Dylan himself once asked Martha on a date, only for Martha to respond with a request to support the bard. He didn’t get back to her… “Oh boy, I’m never going to live that down.”

Yet despite the attention, she still insists she is a songwriting novice. Even last year, with an album adored by critics the world over under her belt; she declared at a gig at the Bloomsbury Theatre that she “was still trying to see if she could write songs”.

A year on, she still seems unconvinced by her own potential: “I find it hard to write songs. I have written a few good ones though. I don’t have a secret formula, I need to try harder”. When asked about the prospect of a possible Rufus-Martha album, she says she “has a little more work to do” until she is able to, the implication is, perform at his level. It is difficult to detect if all this is a charming exercise in deference and modesty, or a genuine ignorance of her own talent.

The new album is almost in the bag. “It’s been a very different process (to the first album),” she said. “There are three different producers and it’ll be interesting to see how it all comes together. I think it is a departure but still recognisable. Trying to make sure the record can flow is the hard part. I guess it might be a little less singer-songwriterly.”

She confesses that the first record was about “unrequited and lost love”. The subject matter of the second promises to be a little different, as, like her brother, her personal life is settled and happy. Yes, Martha is getting married. The lucky beau is Brad Albetta, producer of her debut and one of the three working on the new one.

Preparations are going, err, ok. “I’m not a great planner. It’s not natural to me. I’ve sure I’ve made it harder for myself with my terrible organisational skills!”

One wonders what the themes of the new album will be – it is difficult to imagine a huge leap away from the stunning visceral immediacy of her first, but perhaps it will be more reflective – less of a catharsis. We might even, it seems, see her tackling wider themes.

“I have one song on the record that I feel is about the war, and war in general. But it is more couched in poetry and imagery than making a political statement. Perhaps it is more about terror…”

From her responses today, it was soon obvious that she has been having a ball recently. Of course, she recently performed in the Royal Opera House’s production of Kurt Weill and Bertold Brecht’s Seven Deadly Sins – garnering generally good reviews, and adding even more to this young lady’s ever-increasing wealth of experience.

“I was honoured to be asked to do it,” she said. “It was a challenge I embraced as much as I could. It made me realise the freedom I have as an artist when I write my own songs, but at the same time I appreciated the structure that having a character and choreography, as well as songs to sing, can bring. Every performance was different and being on stage with the dancers and the orchestra was something I could never have dreamt of.”

Asking her about her musical influences is to enter a minefield, considering her lineage. Not only did she have the sound of Loudon’s witty folk in one ear when she was growing up, she had her mother’s love of incredibly obscure folk artists in the other.

Today, she mentions Stephen Foster, Cindy Lauper, Etta James and the one artist who can justifiably be said to appeal to all Wainwrights, Leonard Cohen. She goes on to say she has become “a bit culturally void in recent years”, when asked which music, films and books she is enamoured with, saying: “I try and see the beauty and art in everyday struggles”, before lapsing back to that familiar self-effacement, “or perhaps I am a bit too self obsessed…”

Martha Wainwright plays Shepherd’s Bush Empire on 17 August 2007.