Alfaro-Allah was named to the post Monday by Helen Haynes, the city's chief cultural officer, and Philadelphia poet laureate Frank Sherlock, with whom she will study.
The youth poet position was created in 2013 as a way "to give a young person an opportunity to develop and showcase his or her talents in poetry with the guidance of an experienced poet," the city said in a statement.
Alfaro-Allah, a 10th grader, submitted three poems: "Lullabies," about her Chilean grandmother, whom she called one of the most inspirational people in her life; "Mar Adentro," about Ramon Sampedro, a quadriplegic from Spain who wanted assisted suicide; and "Teeth," about the pain of a failed friendship.
Her favorite of the three is the one about her grandmother - her abuela.
"Hush," the poem goes. "Abuela is hiding trumpets in her throat again. . . . You can hear her weep over the busted notes in our lullabies."
Alfaro-Allah was inspired to begin writing poetry in 2012 by the poet Denice Frohman, who came into her ninth-grade drama class and recited three poems.
"I just wanted to be able to tell my story and tell other people's stories and have people be in awe by it, because I was in awe of what she could do," the teen said.
The next day, she joined the school's poetry club.
This year, she helped the school's slam poetry team win the Philadelphia Youth Poetry Movement Slam League contest, said Matthew Kay, a teacher at the school and slam league coordinator.
"She actually did the performance that broke the tie," he said. "She won in a very high-pressure situation."
She had been on the school's team for two years and mentors younger students, Kay said.
"She does a good job of staying humble and doing everything asked of her and beyond," he said.
Philadelphia's first youth poet laureate was Siduri Beckman, a Masterman School student who was 14 when she won the prize last year.
Alfaro-Allah, whose term as youth poet laureate runs through next May, beat out two other finalists for the honor: Matthew Ridley and Sabrina Slipchenko, both from Northeast High School. With the honor comes a $1,000 stipend.
Chris Lehmann, principal of Science Leadership Academy, called Alfaro-Allah "a wonderful pick."
"She's an amazing, intelligent, creative, passionate voice," he said. "She has a joy for learning and for living that is just wonderful."
'Abuela is Hiding Trumpets ...'
Abuela is hiding trumpets in her throat again
trying to scream through broken orchestras
playing symphonies out of tune in her
esophagus if you listen
You can hear her weep over the busted
notes in our lullabies.
Set between teeth and tears that mangled themselves
through her ribcage and dropped dumbbells
inside of her chest
On mornings that reminded her of home"
- Excerpt from "Lullabies," Soledad Alfaro-Allah's bilingual poem about her grandmother ("abuela")