Maria Shriver and Bono
Chelsea Lauren/FilmMagic, Kevin Mazur/WireImage
She's already leaned on
her close friend Oprah Winfrey
for help, and now Maria Shriver is getting some unexpected support from yet another famous pal – Bono.
By coincidence, Shriver, 55, bumped into the U2 frontman, 51, on Thursday after lunching in Santa Monica.
"Maria lit up when she saw Bono," a source tells PEOPLE. "They hugged several times ... Bono acted very caring and even walked Maria to her car. They again embraced before a smiling Maria drove off."
Bono is a longtime family friend and even sang at the funeral of Shriver's father, Sergeant Shriver. The musician also helped Maria's brother, Bobby Shriver, found the RED Campaign to fight AIDS in Africa.
Maria – who split from husband Arnold Schwarzenegger who's admitted he fathered a child
with another woman – had been dining on a light lunch at The Ivy with an apparent business associate, the source tells PEOPLE.
After Shriver parted ways with her rocker pal, she met up with her other support base – her kids. "Grabbing some dinner with my sis and the best mommy," her son Patrick Tweeted
Shriver has four children with Schwarzenegger: Katherine, 21, Christina, 19, Patrick, 17, and Christopher, 12.
Meanwhile, the former governor of California is spending downtime at his house in Sun Valley, Idaho.