Merril Bainbridge, your first single has just hit No. 15 on Billboard’s pop chart, what are you going to do next?

“I don’t know, really. I just hope that after this promo tour is over and my live tour has ended that I get to go home for the holidays. I miss my family.”

That’s the price the Australian singer-songwriter has paid – willingly, of course – for having a smash with “Mouth” and the recent release of her debut album, “The Garden” (on Universal).

After six years of performing in a variety of bands down under, some doing covers and others original material, and doing backup vocal work in exchange for studio time, Bainbridge now thinks everything is happening so quickly. She insists on enjoying every minute of it.

“Even in my short time in this industry,” Bainbridge said recently from Universal’s New York headquarters, “I’ve seen so many talented people, whether it be in a live situation or when I was working in the studio and different bands would be recording. I feel very fortunate, very lucky that I’ve gotten to this stage.”

It began two years ago when “Mouth,” an amiable pop song about relationships, was released in Australia but got lost in the Christmas shuffle. It was reissued in February 1995 and quickly became the first debut single by an Australian female artist to reach No. 1 there. It stayed atop the chart six weeks. “The Garden,” meanwhile, was certified double platinum.

“That’s when it first hit me, that this was really happening,” Bainbridge said. “I mean, I went out and celebrated when it hit Top 20 there. I thought that was great, but then it just kept going up. I’m like, ‘Oh, no, this is unbelievable.’ It happened so quickly, I was like in a dream state the whole time.

“Fortunately, having experienced that in Australia, I came over here with the attitude that I’m going to enjoy myself and really take notice of everything and savor it. You’re suddenly thrown into this whirlwind of work, and so often it can be so overwhelming that you can’t really enjoy it. And you think when it’s kind of over that you wish you had enjoyed it.

“There’s no textbook for anything in this industry. Every artist has a different path to some degree. You’re on your own. One thing I’ve learned is to always please myself and make sure that I’m happy doing what I’m doing.”

Bainbridge credits her parents for raising her in a positive environment in their native Melbourne. It served her well when she decided to pursue a singing career, eventually meeting producer Siew at 001 Studios.

“We really connected well, from a creative point,” Bainbridge said. “I liked the way he worked and I knew I had so much more to learn in that environment, so I offered him my backing vocal skills in trade for studio time. That’s how it started. That was the point where I started feeling a lot more confident as a singer and then wanting to dive more into the songwriting side.”

She enlisted Siew to produce a demo tape that included “Mouth,” then won a label deal with the Australian label Gotham. The rest is pop history.

Thumbing through Billboard, Bainbridge still can’t believe “Mouth” is perched at No. 15 (and climbing) after only eight weeks.

“It’s fantastic, what can I say? It’s such a gamble, you have no idea what’s going to be a hit,” she said. “You don’t think about that when you’re writing it. If you do, you’d go crazy.”

BWF (before we forget): “Mouth” reached No. 4, stayed on the chart for 30 weeks and achieved gold status.