The actress – due in March with a second son – says showing off her legs makes her "feel hot"

Credit: Axelle/Bauer-Griffin

How can an expectant mom stay stylish in her second trimester? Accentuate the positive, says Jenna Elfman.

Wearing a clingy sweater dress that showed off her toned legs, the actress told PEOPLE about her sure-fire pregnancy style strategy at Monday’s premiere of Old Dogs.

“I found I m showing the things that are still intact,” Elfman, 38, says. “That helps with my beauty morale. The legs and the arms – those are hanging in there, I ll show those. That makes me feel like I m still sexy despite my whole center of gravity being completely altered.”

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For those who may not have killer gams like Elfman’s, she has some advice: “Show what you feel hot about. For me it’s legs – they re hanging in there, barely!”

Elfman, whose new show Accidentally on Purpose has just been picked up for the season, says that she s feeling better after battling morning sickness in the first months of pregnancy with her second son, who is due in March.

“I ve been good actually,” she says. “I finally feel like I have some energy. … Normal and good.”

The actress also says she and husband Bodhi Elfman have managed to nip sibling rivalry in the bud with their elder son, Story Elias.

“He gets it,” Elfman says of 2-year-old Story. “He gives the belly kisses, he lays his head down and says, ‘Night night, baby’ and puts the blankie over my belly. So he s got it. He s amazing.”

Accidentally on Purpose airs Monday nights at 8:30 p.m. on CBS.