One role just isn’t enough for Sarah Michelle Gellar. On her freshman CW series Ringer, she co-stars in two of them, both identical twins and both in serious trouble.

But that isn’t all for Gellar, who also plays a leading off-camera role as an executive producer of the 9 p.m. Tuesday show.

Even so, the demands on her weigh lighter these days than during Buffy the Vampire Slayer, where she labored for seven seasons.

“I work shorter hours on this show – everybody does – than I did on Buffy,” she says with satisfaction. Efficiency reigns on Ringer. Her actors and crew members are fellow pros who help get the job done smoothly. She’s having fun.

Meanwhile, she’s keeping work in healthy balance with her private life, enjoyed with her husband of 10 years, actor Freddie Prinze Jr., and their 2 1/2-year-old daughter, Charlotte.

“When Charlotte was born, Freddie was on 24 and I didn’t work for two years,” says Gellar. “I had asked him, ‘When I’m ready to go back to work, will you stay home with her then?’ He was like, ‘Fine!’ ” She laughs. “He loves it. I think I’ve created a monster!”

On Ringer, Gellar plays Bridget Kelly, an ex-stripper on the run after witnessing a mob hit, as well as her troubled New York socialite twin sister, Siobhan Martin, whose own brewing problems compel her to fake her own death. With Siobhan’s apparent death, Bridget claims her ritzy life and handsome husband in an effort to hide in plain sight from mobsters and the law.

Portraying two characters (plus Bridget masquerading as Siobhan) isn’t so hard, she says.

“It’s a group effort – hair, makeup, wardrobe. Besides, as identical twins, Bridget and Siobhan have characteristics that are inherently very similar. So you don’t have to worry – they have to be able to be confused for each other.”

Her biggest challenge: “keeping in mind who knows what and who doesn’t know what.”

As an executive producer, Gellar knows everything. She notes that the seemingly convoluted story line has been charted out for three full seasons. There will be no false moves or narrative blind alleys tripping up the writers as they turn out weekly scripts.

“I realize viewers have gotten really frustrated with shows that set up a lot of questions but never answered them,” she says.

On Ringer, revelations come weekly, with a major reveal scheduled for the March 13 episode: Viewers will find out why Siobhan went on the lam.

“We would never set up a question if we didn’t know the answer,” Gellar vows. “You have to take my word for it – even my husband doesn’t know – but we do know where it’s going.”

Although the job is grueling, Gellar’s added responsibilities as producer reduce rather than increase the burden, she says.

“I don’t have to waste time worrying about what they’re doing with my character and my story line. I get to make the show I want to make,” she explains. “And since I’m on-set most of the time, if there’s a decision that has to be made while we’re shooting, I can make it, as opposed to calling upstairs. So I can help keep things moving along.”

At 34, Gellar is a show-business veteran. Discovered as a 4-year-old in a Manhattan restaurant, she made dozens of commercials as a youngster. She spent a couple of memorable years on the daytime drama All My Children playing Susan Lucci’s 15-year-old daughter, whose multiple marriages, seductions, attempted suicide and coma helped Gellar score a 1995 daytime Emmy award.

Then, in 1997, Buffy the Vampire Slayer premiered with a bang.

With that high-profile performance by an overnight star in her late teens, Gellar could have fallen prey to prying reporters and tabloid-fueling misbehavior. But with nothing to hide, she says, she chose to keep her tidy private life private, and her huge fan base understood, respecting the boundaries she set.

“But that can get tricky in the age of reality shows and Twitter,” she says. “I think what happens is, you give an inch, and then you kind of owe people a mile. For instance, you can’t do a reality show and then claim the right to privacy – it doesn’t work that way.”

So don’t look for Gellar Family Values or Freddie Loves Sarah Michelle on future TV schedules.