She also had compulsive idiosyncrasies. Shilpa insisted on eating her meals at the same time every day, her brother said. After dinner each night she would walk around the house for half an hour listening to her Sony Walkman.

Marathe said he thinks now that Shilpa was showing signs of mental illness as far back as junior high school. At the time, just a child himself, he dismissed the signs as typical of his “weird sister.”

By the time Shilpa graduated from law school at U.C.L.A. (magna cum laude, of course), she was down to 55 pounds, Marathe said. He remembers that firms eagerly invited her for job interviews after reading the incisive legal papers she wrote, but no one would hire her after seeing her in person.

Shilpa spent her final 10 years living with her parents. She died at 31 in March 2005.

It took Marathe years to emerge from a cocoon of secrecy. He had friends who never met Shilpa. That included his wife, Jennifer, who Marathe said became his best friend when they were at the University of California, Berkeley. In retrospect, he sees his own vanity.

“I was a kid,” Marathe said. “I was in my early 20s, and I used to convince myself that I was just a protective little brother when I saw other people looking at my sister the way they did. When in reality, the truth was that I was embarrassed by being seen with her. So I could never take her to a coffee shop or a movie. I used to be jealous of my cousins who would be able to do that.”

Marathe is now on the board of directors for Andrea’s Voice, and he has supported other similar organizations in Northern California, like the Eating Disorder Resource Center and the Monterey Institute of Mental Health.