She’s still a little bit country, and a little bit . . . opera?

Marie Osmond performing at Foxwoods with brother Donnie Osmond.James Reed for the boston globe/James Reed

Their well-scrubbed faces were a fixture throughout the 1970s, first with legions of bell-bottomed girls swooning to Donnie Osmond’s “Puppy Love,” and then with little sister Marie’s turn on the charts chirping the gingham-and-lace-tinged “Paper Roses.” The siblings joined forces for a blockbuster variety show in the late 1970s, followed by a post-variety show afterlife with a career list that reads like an entertainment smorgasbord: Broadway, “Dancing with the Stars,” doll designing (Marie, not Donnie), a talk show, and, for the past eight years, a standing gig at the Flamingo in Las Vegas.

Donnie just released his 60th album, Marie is about to release “Music is Medicine,” an album that includes a big show-stopping number, plus a duet with Sisqó — yes, the “Thong Song” lothario. No word on what the dolls think of the Sisqó duet.

“It’s been a while since I recorded an album,” Osmond said backstage after a recent performance at Foxwoods Resort Casino. “People say once you’re over 30, you’re done as a female artist. I’m not. I have a lot of things to say that I could not say when I was 30. Olivia Newton-John is on the album with me, John Rich did a song with me that’s fantastic, Alex Boye, who is huge on YouTube is on there, he’s phenomenal.”

We sat down with Marie to talk about Las Vegas, opera, and Sammy Davis Jr.

Why do you think that you and Donnie have such a good rapport with Vegas audiences? It takes a certain type of entertainer to work that kind of a room. You can’t just stand there and sing. We grew up on the tail end of what I call the great entertainers. They really knew how to work an audience. Frank Sinatra, Sammy Davis Jr., I mean, you can’t imagine. I learned from Sammy Davis Jr. It’s ridiculous. Donnie and I both translated that show into that room, so it’s really fun. We enjoy it.

Did you have any hesitation about performing with Donnie again? Absolutely. Are you kidding? Donnie and I had not sung together in 28 years. I was doing my solo stuff and I had a bunch of country hit records, and he was doing his stuff and “Soldier Of Love.” Then we had this opportunity in Vegas for six weeks, and we thought, well, that could be fun. We haven’t worked together in forever. Now we’re starting our eighth year.

Even though the two of you are ribbing each other on stage you must be enjoying it. You can’t divorce your brother. No really, there is that sibling energy that I think we have that’s very unique. We can get away with dissing each other.

You’re best known for your country albums, but I don’t think people are aware of your range. I do opera, I do legit soprano, I sing all those styles in Vegas.

What do you mean opera and legit soprano? What do you sing? I did “The King and I,” so I learned to do legit singing. Then while I was studying that they realized I could do opera, so I sing “Nessun Dorma.” I have a loud voice, you heard. I did “Pie Jesu” and softer ones, but I do “Nessun Dorma” right now in Vegas and it’s really fun, very loud.

You said that this might be your last year in Vegas? We take it year by year. But I haven’t stopped working since I was 3. People take hiatuses, but I’ve never taken a hiatus.

Take a hiatus, Marie! I think you’ve earned it. I think when people stop, they’re done. I know when I stop, I’ll stop. I don’t feel like stopping, Not yet.