Credit: Swarbrick/Donnelly/

Peekaboo, it's Penelope!

Tina Fey and composer husband Jeff Richmond took advantage of NYC's indian summer temperatures on Monday to check out the Botanical Gardens in the Bronx.

The Emmy-winning 30 Rock star, 41, brought along daughter Alice, 5 -- and Alice's little sister Penelope Athena, born Aug. 10.

Us Weekly has the first-ever photo of the adorable little girl, bright-eyed and chubby-cheeked in her stroller as she checks out the first glimpse of fall foliage with her family.

Five weeks after Penelope's birth, a svelte Fey turned up at the Sept. 18 Emmy Awards and told Us Penelope was "doing great," and that sibling Alice is "an amazing big sister."

Saturday Night Live alum Fey announced her second pregnancy during an April taping of The Oprah Winfrey Show, and wrote about the idea of a second child in her memoir Bossypants.

"I thought that raising an only child would be the norm in Manhattan, but my daughter is the only child in her class without a sibling," Fey wrote. "Most kids have at least two."

She fretted: "Who will be my daughter's family when my husband and I are dead from stress-induced cankers? She must have a sibling."