Yes, the Olsen twins were that young when they first starred on “Full House.”

Twins playing one child character was not unusual then and still isn’t today, as of this writing.

Using twins to play one character doubles a show’s opportunity to feature that young character on screen.

Mary-Kate and Ashley Olsen

By 2015, they shared the title of Womenswear Designer of the Year.

John Stamos with Olsen twin and Dave Coulier in Full House

Mary-Kate and Ashley Olsen