Jordin Sparks’s step-sister has died.

The singer’s step-sister Bryanna Jackson-Frias, 16, died Tuesday evening of complications from her lifelong battle with sickle cell anemia, which causes red blood cells to stick to vessel walls, blocking blood flow and preventing oxygen from reaching tissues; the lack of oxygen can damage organs and cause pain so severe it requires hospitalization.

“Bry went peacefully to Heaven,” Sparks’s mom, Jodi Jackson, wrote on Facebook Wednesday alongside a photo of her late step-daughter. “I can’t help to think [that] she’s smiling just like this. Thank you all for your prayers.”

Sparks, 28, first revealed Bryanna was suffering a sickle cell episode on Tuesday.

<p>Jordin Sparks</p>

Instagram 

“Please keep my little sister, Bryanna, in your prayers,” the American Idol alum captioned an Instagram Story. “She’s suffering from complications from sickle cell and is in the ICU fighting for her life.”

The sad news comes just months after Sparks revealed she was secretly married and expecting. In November, she exclusively told People she quietly married model boyfriend Dana Isaiah, 25, in July; the pair will welcome their first child—a son—this spring.

The family asks that in lieu of gifts, donations be sent to El Paso Children’s Hospital.