Paris Hilton Says Sister Nicky's Newborn Daughter Has Given Her 'Baby Fever' (Exclusive)

ET spoke with the famous sisters at the New York screening of 'Black Panther' on Tuesday.

Nicky Hilton Rothschild is the proud mother of two beautiful little girls, and the abundant cuteness is making her famous sister, Paris Hilton, think about starting a family of her own.

ET caught up with the socialite siblings at The Cinema Society's premiere screening of Marvel's Black Panther in New York City on Tuesday, and the new mom gushed over her precious little bundle of joy, Theodora "Teddy" Marilyn.

"She's good. She's very tiny. She's eight weeks," Nicky shared. 

On Monday, the 34-year-old heiress posted the first photo of her daughter to Instagram, writing, "Kisses + cuddles before out the door to catch the @oscardelarenta show."

After giving birth less than two months ago, Nicky is staying fit and healthy -- a feat that seemed to impress her sister.

"You literally cannot tell," Paris, 36, marveled.

The former reality star admitted to ET that seeing Nicky with her newborn daughter -- as well as her and husband James Rothschild's 1-year-old little girl, Lily-Grace Victoria -- has given her "baby fever."

"Also it gives me hope, because I know she has amazing genes, it runs in the family, so I'm not gonna have to worry," Paris joked.

While she and fiancé Chris Zylka aren't gearing up for parenthood just yet, Paris said that wedding planning is in full swing.

"I'm finally looking for my wedding dress so Nicky and I have fittings this week," she revealed. "And she has such beautiful taste that I can't pick the wedding without my maid of honor."

Being her sister's maid of honor is a responsibility that Nicky said she really enjoys.

"I'm loving it," Nicky shared. "I'm most excited for [planning] the bachelorette party."

ET caught up with Paris and her soon-to-be-husband back in January at HBO’s Golden Globes after party, where the happy couple admitted that they want to tie the knot "as soon as possible."

Check out the video below to hear more about their upcoming wedding plans, and to get  a look at Paris' stunning engagement ring.

Marvel's Black Panther hits theaters Feb. 16.