Canadian lyric soprano Erin Wall has become a favourite with Edinburgh Festival audiences, but then she is a very well-travelled woman, with friends in many cities in Europe and in Australia, as well as across North America.

Having small children - her daughter is just 18-months-old and her son not yet five - has not stopped Wall clocking up the air miles in recent years, often with a baby in tow.

Of her Edinburgh appearances, there was the closing concert of last year, singing Verdi Requiem with Donald Runnicles and the BBC Scottish Symphony Orchestra, and her 2011 Thais with the RSNO under Sir Andrew Davis, which was rapturously received. It is her established working relationship with that conductor in various locations around the world that Festival audiences will see again at the Usher Hall on Thursday when she sings the Four Last Songs of Richard Strauss with the Melbourne Symphony Orchestra.

That work has recently become a key feature of Wall's repertoire. She sang the songs in January with the City of Birmingham Symphony Orchestra and Andris Nelsons - a partnership that made it to the Sage in Gateshead but not over the Border - and the Melbourne/Davis concert travels on to the Concertgebouw in Amsterdam after Edinburgh.

"It is one of the things I do want to do more of." she says, "It is a little like eating dessert for every meal."

This from a woman who is very careful of her diet and is a runner. Her most recent entry on her website ends: "I have a half-marathon scheduled next month so I'm trying to work running back into my busy singing schedule. There's no better way to see a city during a packed touring schedule, and all you need to pack are your running shoes."

Flying and running, Wall made a stop-off in Glasgow (as well as Edinburgh) at the start of the city's Commonwealth Games celebrations, singing Mahler 8 in the company of other soloists from the participating nations, again with the RSNO, but with the orchestra's music director, fellow-Canadian Peter Oundjian, with whom she has also worked frequently.

It was her 16th Mahler 8, the so-called Symphony of a Thousand, another work that has become a calling card. Invitations have come to sing it around the world since her first performance in 2006, and include a Toronto performance with Oundjian in 2012. "I love it," she says simply. "That first one changed my life."

Wall's professional life does seem to be full of such game-changing moments. The most famous of these was a decade ago in Chicago. After studying in Vancouver and being a finalist at the Cardiff Singer of the World competition in 2003, Wall was understudying the role of Donna Anna with Chicago Lyric Opera when Finnish soprano Karita Mattila was taken ill before the opening night.

"I got a call the day before, so I had some rehearsal time. I had a costume fitting and a sing-through," she remembers. "But I got great notices the next day - audiences were very supportive." She has been asked to sing the part many times since, and takes the role in Seattle in October and in Munich in January,

Wall describes herself as a slow starter who had no real aspirations to a stage career as a teenager although she sang alto in the school choir and played piano and flute.

She was more interested in singing jazz until she went to voice lessons and was encouraged towards classical singing, and her high soprano voice was revealed.

"The bottom of my range just went away completely with the coming of age," she says. Now she has covered a "good chunk" of the Mozart roles, and looks forward, as so many sopranos do, to the opportunity to sing the Marschallin in the great Hofmannsthall/Strauss opera Der Rosenkavalier.

More immediately, however, she is looking forward to work on a newer opera next year that might have been an appropriate addition to this year's Festival.

American composer Kevin Puts's debut Silent Night won the 2012 Pultizer Prize for Music and is based on the story of the Christmas truce during the First World War.

Premiered by Minnesota Opera, the original production is being revived in Kansas in February and March of next year with Wall in the lead role of Danish opera singer Anne Sorenson, whose fiance goes off to the front, before she herself goes there to entertain the troops.

Walls says: "I saw it in Texas when I was there doing a Mahler 8 and so far it has only been done in Canada and the US," adding that a significant proportion of the roles are specifically Scottish soldiers, around whom the plot, and the seasonal cessation of hostilities, revolve.

Whether or not Jonathan Mills considered Silent Night for his First World War Centenary festival, perhaps it is a work that Scottish Opera might look at adding to its schedule? There is a certain soprano who is very popular in Scotland who will soon be familiar with the role.

Erin Wall sings Strauss's Four Last Songs with the Melbourne Symphony Orchestra and Sir Andrew Davis at the Usher Hall on Thursday evening.