Daytime-TV grand dame Jeanne Cooper, who played The Young and the Restless‘ Katherine, passed away on Wednesday morning after being hospitalized, off and on since April, for an undisclosed illness.

Cooper’s elder son, actor Corbin Bernsen, shared the sad news on Twitter, saying, “She was in peace and without fear. You all have been incredible in your love. In her name, share it today with others.”

Mom passed this morning. She was in peace and without fear. U all have been incredible in your love. In her name share it 2 day with others. — Corbin Bernsen (@corbinbernsen) May 8, 2013

Bernsen just last week updated his mother’s fans via Facebook, upon her latest return to the hospital: “I said goodbye to her [Friday], and even then not fully meaning it or expecting that would be the last time I saw her. But now it will have to do, as we enter this weekend letting her final voyage begin…. I don’t want her in pain. I don’t want her in fear or agony…. So I’m giving her this weekend — take the holiday, Mom, make it yours, let it take you where it will. My final words to her last night were, ‘I’ll see you again.’ And I will, either here or there.”

Best known for her nearly 40-year run on CBS’ Y&R, which launched in 1973, Cooper’s career began in the 1950s with a role in the Western The Redhead from Wyoming. She then launched into a long string of roles on TV anthology series — including ABC’s Crossroads, NBC’s Tales of Wells Fargo and CBS’ Dick Powell’s Zane Grey Theater — and dramas such as The Adventures of Kit Carson, Cheyenne, Wagon Train and multiple appearances on Perry Mason, The Big Valley and Ironside.

On Y&R, Cooper played high society doyenne Katherine Chancellor (as well as, now and again, her lookalike Marge Cotrooke). The actress famously invited the daytime drama to weave in storylines mirroring her own life, including a mid-1980s facelift (the show used footage from Cooper’s actual procedure) and a recurring bout with alcoholism. The character of Kay also crossed over to sister sudser The Bold and the Beautiful for two episodes in 2005.

Over her career, Cooper amassed 10 Daytime Emmy nominations, winning once in 2008 after earning a Lifetime Achievement Award in 2004. She also netted two Primetime Emmy nods, including for her turn as son Corbin’s L.A. Law mother.

Cooper took a brief medical leave from Y&R in October 2011, at which time her part was temporarily recast with Michael Learned (The Waltons).

The actress is survived by her three children, Corbin, Colin and Caren.