In the middle of shooting My Sister’s Keeper Diaz’s father died from pneumonia, halting production for two weeks.

LOS ANGELES — From the window of the sunlit suite where Cameron Diaz sits, there is a beautiful view of the Santa Monica beach with blue sky, fluffy white clouds above. The 36-year-old star is dressed to match — a lightweight white sweater with thin blue horizontal stripes, white slacks.

She seems relaxed and happy.

“That’s how I feel inside,” she smiles. “I’m glad that it shows. I like to put nice things out in the world.”

Last year at this time was different. The unexpected death of her father, Emilio, at 58 from pneumonia, had shaken the Long Beach native, who was in the middle of shooting My Sister’s Keeper. The film, which opens Friday, deals with death, too. Diaz plays a mother, Sara, whose oldest daughter, Kate (Medium’s Sofia Vassilieva) is stricken with cancer. She and her husband (Jason Patric) have conceived a second daughter, Anna (Abigail Breslin), a bone marrow match for Kate, but when asked to donate a kidney to save Kate, the 11-year-old Anna balks.

Directed by Nick Cassavetes (The Notebook) from a novel by Jodi Picoult, My Sister’s Keeper may seem like a ready-made tearjerker, but it addresses some interesting issues regarding medical ethics as well as delves into the family dynamic.

Diaz left the set for about two weeks in April after her father died. (Production shut down for a while and then they shot around her.)

“For me, this last year has been the most important year of my life,” says Diaz, her voice growing quieter the more she talks about the experience.

“So I’ve been very fortunate to have time to be with my family and be with myself and I’ve learned many lessons this year that unfortunately I couldn’t have learned without that loss. I believe that if something so great has been taken from you, or goes because that’s the course of nature — my father was going to have to die at some point — there has to be gifts in that,” says Diaz, who with her sister would often watch sports with their father.

“Although my father is dead, which really sucks, other than that, there are good things in life.”

Diaz credits Sister’s cast and crew for helping her when she went back to work. “Literally, the girls (Abigail and Sofia) helped me. Nick was amazing, too. That’s really the only way that I was able to do it.”

Cassavetes says he cast Diaz because she “represents the innocence of youth. Before my own kid got sick (with congenital heart disease), I was a happy person. I didn’t have tattoos all over my body, and I didn’t have the temperance in my soul that I do right now. Cameron seemed like a perfect fulcrum for everyone who is completely unprepared for what is about to happen. Plus, she’s simply awesome.”

The actress, who began modeling at 16, got her first break in the 1994 Jim Carrey film The Mask and has been a sexy, comic screen presence ever since (There’s Something About Mary, Charlie’s Angels and the voice of Fiona in Shrek). Although she has taken serious roles (Gangs of New York), playing a mom is not something associated with her. Still, she says, she didn’t think about it when she took the role.

“I was so enthralled and completely taken by the story.”

Part of what fascinated her was her character, Sara, who is obsessed about saving one daughter at the expense of possibly the family.

“I don’t believe Sara thinks that God is on their side. I don’t think that she believes she can have faith. Whenever something like this happens, I believe that trauma stunts growth. Hearing her child was going to die just sent her in one direction. … I can’t judge her because I don’t know what it’s like to be in that position. I do know what it’s like to be human, to make a mistake, to not see the biggest picture. Sometimes we get narrowly focused on things because we’re hurt or we’re fearful and we think that the only way something can happen is what we convince ourselves is the right way.”

Asked if she’s religious, Diaz says she wasn’t raised with a religion. “I was raised with faith … spirituality. I have a deep faith, for sure.”

These days, Diaz seems to be comfortable in her own skin and not worried about the aging-actress syndrome. “I think it’s a privilege to get older. Not everybody gets that privilege and I hope to.”

But reporters worry about it.

“I’m not 25 anymore,” she points out to a group of them earlier in the day. “I could have a 16-year-old child; I might if I was a different person.” She adds with her offbeat sense of humor, “I’m sure I have a few out there that I don’t know about.”

That last comment is no doubt in response to the constant questions by the paparazzi about who she’s dating. She seems a bit disheartened when it’s mentioned that bloggers were jumping on an offhanded comment she made in a Marie Claire magazine article. While much of the lengthy piece was devoted to a four-day trip Diaz took to interview people for a short film for the magazine about the failing health of our planet, Internet headlines were about her butt.

“I’d love a bigger butt, more meat on my bones,” she told the interviewer. “I’d love to be more voluptuous. It’s just not my body type.”

Some of the postings didn’t even mention what the article was about or even the second part of the quote about her body type.

“It just shows that some people are too concerned with the wrong things — minimizing makes us all smaller,” says the actress, who says that while growing up she could see flames from a refinery from her house and remembers her dad dusting all the time because of all the dirt that came in.

After having attended a TED (Technology, Entertainment, Design) conference in which the leaders in their fields discussed innovation, Diaz began to wonder “what it would take for people to be engaged in shaping their future.” So for the film, the actress interviewed a number of people, many of them living in the shadows of refineries like the one near her childhood home.

“What I found when I went to Cleveland and Houston was that there were maybe three people out of the hundred or so I spoke to who actually knew where their food or water or air came from … I think it’s interesting that we’ve given over the three things that keep us alive to total strangers. It’s responsible for a lot of things that are happening in our society — our health, how sick we are as a nation, cancer and diabetes, obesity. All those things that we have control over if we just paid attention a little bit more and asked for something different. We are in a democracy. We can shape and form our future.”

Diaz is quick to say she doesn’t have the answers.

“I just wanted to pose a question for people to ask themselves.”