Ruby Rose is sharing a deeply personal glimpse into what she says was Hayden Panettiere's private pain before the actress died at 36.

A huge company has apologised for firing Hayden Panettiere after she spoke out about her battles, but only after her death sparked a boycott campaign.

"Today is Hayden's birthday," he wrote. "Instead of celebrating the way we had planned, today we celebrate her life, her spirit, and the love she brought into this world.