Donating her file cabinet, full of old journals, letters and zines to New York University’s Fales Library archive was a bittersweet move for Kathleen Hanna. A singer and founder of the riot grrrl band Bikini Kill and the feminist electro-pop act Le Tigre, Ms. Hanna had been a den mother to contemporary-girl culture for a generation, but she was still only a midcareer artist, too young to grapple with archiving her work. The donation helped legitimize the riot grrrl movement.

But Ms. Hanna, 44, had more personal reasons for securing her legacy: She wasn’t sure how much longer she’d be around.

Timing has played a big part in Ms. Hanna’s creative life since she emerged from the DIY scene in Olympia, Wash., in the early 1990s. The brief but influential riot grrrl movement seemed to arrive at just the right moment, during debates about workplace harassment and young women’s sexuality, fresh issues that still resonate today. But over the last few years, even with a ‘90s revival in full swing and her view in high demand, Ms. Hanna had all but disappeared from public life.

The reason for her absence, as she is just beginning to reveal, was illness, depression and artistic flux. “I’m still not sure, day to day, if I’m going to wake up and be really sick,” she said.