'Clueless' Actress Elisa Donovan Remembers 'Sweet' Costar Brittany Murphy as 'Like a Hummingbird'

Almost 26 years after making Clueless, Elisa Donovan's memories of playing Amber Mariens both in the 1995 film and its subsequent television spin-off are as strong as ever.

Chatting with PEOPLE amid the recent release of her memoir Wake Me When You Leave, the 50-year-old actress recalls Clueless as being "the first time I had ever done a major studio film." And for her, the show, which aired in the '90s for three seasons, was even "more enjoyable" despite longer hours filming, because her part was bigger.

Donovan also reveals that she still keeps in touch with several of her Clueless costars from both the film and TV show (especially Donald Faison, who played Murray Duvall).

One original cast member from the movie who made a cameo in the series? Brittany Murphy, who did not reprise her role as new girl Tai Frasier but appeared as Jasmine in one episode.

Remembering the late actress as "a really sweet person" and calling the loss of her friend "very sad," Donovan adds of Murphy, "I always think of her like a hummingbird. She just was an incredibly talented girl with a great spirit."

Murphy died after collapsing in the bathroom of her Los Angeles home on Dec. 20, 2009, as a result of pneumonia combined with anemia and "multiple drug intoxication" from prescription and over-the-counter medication, according to the L.A. County coroner. She was 32.

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Today, Donovan — who went on to star on Sabrina the Teenage Witch and in several films, both on the big screen and television — says she still gets recognized "all the time" for her Clueless role, which "always shocks" her.

She tells PEOPLE that fans' "go-to" line to quote in front of her is Amber's classic, "My plastic surgeon doesn't want me doing any activity where balls fly at my nose" — followed by Dionne Davenport's (Stacey Dash), "Well, there goes your social life."

As for whether she'd ever reprise her role should a Clueless sequel be on the horizon, Donovan wouldn't hesitate, as she thinks "it would be hilarious to see these people as adults."

"Amber would probably be running her own fashion line, bossing a lot of people around — and driving a very wealthy husband crazy," she jokes.

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Donovan is flexing her author muscles in her new memoir Wake Me When You Leave, taking readers through some of her life's ups and downs including career snags, her dad's cancer diagnosis and relationship lessons. (The star has been married to husband Charlie Bigelow for eight years.)

"I started writing it when all of these things were happening, but it was quite disjointed and more of something for me to help heal," the former PEOPLE blogger says of her book, out now.

Additionally, Wake Me When You Leave touches lightly on Donovan's previous struggles with disordered eating. Having been open about her recovery, the mother of one says now that she hopes to pass on to daughter Scarlett, 9, "that we are not our physical appearance" and the importance of treating our bodies "with love and with health and strength."

Of advice she'd give her past self, the actress says, "I think all that struggle when we're younger is important. It builds resilience. It helps us discover who we are. Maybe I'd like to tell myself, 'Don't worry — you'll get there.' "

Wake Me When You Leave: Love and Encouragement via Dreams from the Other Side is available now on amazon.com.

For more from Elisa Donovan, pick up the latest issue of PEOPLE, on newsstands Friday.