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Jennifer Lopez's heart is apparently as big as her wig collection.

Jennifer Lopez dedicates a room to her wigs and other ways stars are nothing like us

The pouty-mouthed star reveals to E! News that a medical scare involving her daughter, Emme, led to her latest charitable effort.

According to Mrs. Marc Anthony, when the tot (and twin sister of Max) was just three weeks old, they discovered a lump on her head.

"We both got very nervous, very very nervous, and I just remember my heart sinking to my feet," she shared on Saturday at the annual Noche de Niños benefit for Children's Hospital Los Angeles. "I looked at [Marc] and I said, 'You know if anything happens, I'm not going to be OK, you know that, right?'"

They made a beeline for Children's, where Emme underwent an MRI exam and several other tests. Thankfully, everything "turned out fine," says J.Lo, but the frightening experience got her thinking.

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"I started to wonder, what if I couldn't afford a doctor or receive the medicines, the procedures?" recalls Lopez, who soon decided to team up with the hospital to establish the Maribel Foundation, which offers pediatric medical assistance to those in need.

(By the by, Jennifer also helped raise $127,000 for the hospital by participating in a Malibu triathlon last September.)

Photos: Jennifer Lopez

Also in attendance at the Noche de Niños benefit was Jamie Lee Curtis, who received the Courage to Care Award from her "True Lies" co-star, Gov. Arnold Schwarzenegger (even after all this time, that still sounds weird to us).

The actress, who thanked Ahnuld by planting some sugar on him, was sporting a hot pink wig straight out of Britney Spears' aimless-driving, gas station-stopping, British accent-spouting phase, but the hairpiece wasn't an homage to the popster's train-wreck period.

Instead, it was a tribute to its previous owner, a 15-year-old named Katie Westbrook, who died of cancer in 2001.

"We were at a news conference, and she pulled off this wig and on her head she had written 'Jamie Lee Curtis Rocks,'" the actress recalls to E! of first meeting the then 11-year-old Katie, whose picture she carried on the red carpet (the two ended up becoming good friends). "That night I borrowed her wig and went to this event, where we raised millions of dollars for Children's Hospital Pittsburgh. After she died, I asked her mother if I could have her wig to carry her message."

And finally, Kate Winslet may not have made room for a freezing Leonardo DiCaprio on her floating board at the end of "Titanic," but now all is forgiven, and the pair are pooling their resources in order to help the last remaining survivor of the 1912 disaster.

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"Access Hollywood" reports the stars have joined with director James Cameron to make a sizable donation to 98-year-old Millvina Dean, who was just nine weeks old when the ship went down. She's now struggling to pay her nursing home bills in England.

Their contribution was prompted by photographer Don Mullan's plea in the Irish Independent newspaper for the major players from the mega-grossing 1997 movie to help. The lensman has been selling a limited-edition photo of Dean to raise funds for her, but he says he decided to "publicly challenge James Cameron, Leonardo DiCaprio, Kate Winslet, 20th Century Fox and Celine [Dion] to match me dollar for dollar."

He's yet to hear from the Canadian belter, who, for better or worse, ingrained the film's Oscar-winning theme song, "My Heart Will Go On," into the world's consciousness, but we have a feeling she'll come through with some cash, if not a massive blue diamond necklace.

Next: Posh goes au naturel