Michelle Pfeiffer on Coming Full Circle With Dakota Fanning in 'The First Lady' (Exclusive)

Pfeiffer, who portrays Betty Ford in the Showtime series, recalls working with Fanning in 'I Am Sam.'

Michelle Pfeiffer is in awe of Dakota Fanning. The 63-year-old actress met the budding actress when she was just 6 years old as co-stars on I Am Sam, and some two decades later they've come full circle on The First Lady.

While at the red carpet premiere for the Showtime scripted anthology series, Pfeiffer recalled to ET's Nischelle Turner about meeting Fanning as a little girl when they teamed up for the 2001 melodrama film, which also starred Sean Penn.

"She turned seven on I Am Sam and I bought her a Barbie Winnebago," Pfeiffer recalled. "And I remember playing Barbies in her camper with she and Elle. And she turned 27 on the set of First Lady." I Am Sam was Dakota's first film, and she'd go on to earn more acclaim just a few years later, starring opposite Denzel Washington in Man on Fire. All these years later, Pfeiffer wondered about Dakota's journey in Hollywood and her coming of age.

"I was so curious to see the kind of grownup that she had become," Pfeiffer said, "and was oh so pleasantly surprised in a way."

The First Lady, premiering Sunday on Showtime, is a 10-episode series created by Aaron Cooley. The star-studded cast includes Viola Davis as Michelle Obama, Pfeiffer as Betty Ford and Dakota as Ford's daughter, Susan Elizabeth. The non-fiction series offers “a revelatory reframing of American leadership, told through the lens of the women at the heart of the White House.”

Pfeiffer also stars opposite Aaron Eckhart as Gerald Ford, and the actress sang his praises.

"I loved working with Aaron," she said. "I've been such a fan of his for so many years and was really excited when I heard he was going to play Gerry Ford. It was wonderful. It was intense and it was fun."

Pfeiffer tells ET she hasn't heard from anyone in the Ford family about her portrayal or whether they've seen the series. Whatever the case, the veteran actress can only hope she served Betty justice.

"I don't know if they sent it to them to see or not," she said. "I'd love to hear from them if they're happy."