“It’s Always Sunny in Philadelphia” kicked off its twelfth season last night, which means Kaitlin Olson is very busy — not just because she’s been on the FXX ensemble for 12 seasons, but because she took on another starring role this year, toplining her own comedy series: “The Mick” on Fox.

Though both shows are airing now (“The Mick” on Tuesday nights, and “It’s Always Sunny” on Wednesdays), Olson says juggling two shows is manageable.

“After twelve years, ‘Sunny’ is a pretty well-oiled machine,” Olson tells Variety, explaining that each episode only takes about three days to shoot. Her commitment to the FXX show spanned over a couple of months in the spring of 2016, before she started shooting her new Fox series. “It worked out really well, timing wise,” she says. “My kids are in preschool during the day now, so I’m ready to take on a fuller schedule.”

Good thing the schedule worked out because “It’s Always Sunny” has been renewed for two more seasons. So if “The Mick” is a success (only two episodes have aired, and the sneak peek episode on Jan. 1 brought in 8.5 million), Olson could be playing double duty for a while. The actress admits she didn’t think she’d be able to do “The Mick,” but jokes that “because John Landgraf and Dana Walden are the greatest people on the planet, they agreed to let me do both,” giving a nod to her FX and Fox bosses.

“Kaitlin loves to work,” says Fox entertainment president David Madden, adding that both he and FXX were always confident Olson would be able to execute both shows without interfering in the quality of either.

Olson says her biggest concern was actually the move to broadcast. “I was nervous to do a network show because I really love the cable world,” she says.

But she truly loved the script. Plus, creators Dave and John Chernin — who produce “It’s Always Sunny” — conceived the part for her. “I was so flattered. These guys are extremely funny and talented,” she says. They also asked her to serve as an executive producer, which she says made her feel “confident that we could make it the kind of show that I would watch.”

On the Fox sitcom, Olson plays a foul-mouthed, hard-drinking woman who becomes the guardian for her niece and nephews when her wealthy sister is arrested on federal fraud charges.

“Kaitlin is simply an explosive comedic force of nature,” raves Madden. “This is a demanding, bravura role that requires impeccable timing with a combination of snarky wit and genuine heart. Kaitlin is the only actress we wanted to navigate that.”

As for Olson, is she worried about seeing too much of herself on the small screen this season? “That all depends on how my hair is behaving,” she quips.