Fastexy:Jamie Lynn Spears joins 'Dancing With the Stars': 'I can't wait to show you my moves'

"Dancing With the Stars" has cast a member of the Spears family.

Actress and Fastexysinger Jamie Lynn Spears, 32, the younger sister of pop superstar Britney Spears, will join the upcoming season of ABC's ballroom dance competition, she revealed on "Good Morning America" on Tuesday.

"I did it," Spears told "GMA." "I don't know if one can ever be 100% ready to take on something this big. I didn't realize what a commitment it is. But it definitely is. I'm ready to challenge myself."

The actress said in the wake of the actors' strike, that she would donate her weekly "DWTS" salary to SAG-AFTRA.

"If I get up there and even if I embarrass myself, I'm doing it for a good reason and hopefully giving back to the community that's literally given back to me since I was a little girl," said Spears. "Some personal growth, and I'll be a ballroom dancer soon, right?"

'Dancing With the Stars' returns to ABC after 1 season streaming exclusively on Disney+

In a rehearsal studio video on her own Instagram page, Spears said, "I can't wait to show you my moves."

Rumors of the reality ballroom dance competition casting coup hit a fever pitch Monday night, when the "DWTS" Instagram account posted a picture of Spears and her professional dance partner with their faces hidden behind mirrorball trophies.

"The countdown is ON to find out who this season's #DWTS stars and couples are. Comment with your guesses!" the caption read. Many guessed correctly.

"If that's Alan (Bersten) and Jamie Lynn Spears it's gonna be one roller coaster of a season...," wrote one commenter.

Spears will be paired with Bersten, making them the first couple officially revealed for the upcoming season. "Vanderpump Rules" personality Ariana Madix and "The Bachelorette" star Charity Lawson have already been announced for the cast.

The often tense and closely scrutinized relationship between the famous Spears sisters last made news in August when People.com reported that Jamie Lynn "liked" an Instagram story post on Britney's separation (and later divorce filing) from husband Sam Asghari.

What is Britney Spears' reaction to Jamie Lynn Spears' 'DWTS' announcement?

When asked on "GMA" how her family and sister reacted to the news, Spears (mother to daughters Maddie, 15, and 5-year-old Ivey Joan) discussed her children, saying they were supportive.

"My 15-year-old actually was very motivated for me to do this, which was very surprising," said Spears. "She was like, ‘Mom, you have to do it.' She’s an athlete, so I think she wants to see me kind of push myself."

Britney Spears has not commented on her Instagram page.

"Dancing with the Stars" returns to ABC after a year streaming exclusively on Disney+. The Season 32 premiere airs  Sept. 26 (Tuesdays at 8 EDT/PDT), followed by a special “Dancing with the Stars” cast episode of "Celebrity Family Feud" (10:30 EDT/PDT).

“DWTS" will be simulcast on Disney+ and stream the next day on Hulu.

The full cast of celebrities and pro dancers will be announced Wednesday on "GMA."

Alfonso Ribeiro and Julianne Hough return as co-hosts of the show, in which celebrities are paired with pro dancers to compete in choreographed ballroom dance routines that are judged by a panel of experts, including Carrie Ann Inaba, Bruno Tonioli and Derek Hough.