Jojo Siwa's youthful energy brings joy to pro partner Jenna Johnson on 'Dancing with the Stars'

FAIRFAX DISTRICT, LOS ANGELES -- Pro dancer and former mirror ball champ Jenna Johnson is thrilled to have 18-year-old JoJo Siwa as her partner for season 30 on "Dancing with the Stars."

"I told this to my husband. This is the first time that I've really looked forward to rehearsal and that's something," said Johnson. "This show is very stressful, but every day is a joy with JoJo."

Siwa says it's something she learned, the hard way, as a very young dancer.

"When I left 'Dance Moms', looking back, I was always nervous. And I missed out on so much because I was always nervous," said Siwa. "So I told myself you're never allowed to be nervous again no matter what."

The top-scoring duo from week one had one slip during their debut performance. It "tweaked" Jenna's knee, but she's been back at rehearsal this week and can't wait to see what's ahead with her young protégé.

"She makes me youthful. I've never felt so old. It's crazy but it's good. She keeps my energy up!" said Johnson.

Siwa laughed: "My favorite thing to do is Jenna will say 'I've been on this show since I was 18 years old' and I say 'yea me too!'"

JoJo and Jenna will be dancing the cha-cha Monday night when they hit the ballroom for round two.