Kaia Gerber was seen out in public in Los Angeles this week for one of the first times since the death of her older brother, Presley Gerber, who died Sept. 20 at age 27, according to Hello! Magazine.

Presley, the son of Cindy Crawford and Rande Gerber, died at a rehabilitation facility in California; authorities are treating it as a suspected overdose, though the Los Angeles County Medical Examiner has not released an official cause pending further testing. He had spoken publicly about a decade-long struggle with addiction, which Kaia described in a Vogue cover story published in August.

A source told Hello! that Kaia is taking her brother's death "very, very hard." The family has asked for privacy as they mourn.