Before these two sisters, proudly waving their USA flags, turned into American actresses, they were just hittin' the sunny beaches of SoCal ... and dreamin' of makin' it big in Hollywood!

They made their names known when they were teens ... One sister made her film debut in the comedy "Mumford" with Jason Lee, while the other sis' debuted in "It Could Happen To You" with Nicolas Cage.

They're probably most known for their roles in "Elf" and the show "Bones."

And when they're not in front of the cameras, they are doting mothers to their kids!