“She’s literally the most beautiful pregnant woman I’ve ever seen in my life,” shares the 36-year-old heiress.
Hilton adds that her sister hasn’t felt “sick” during this pregnancy, explaining, “She is a trooper, and I can’t wait for the baby.”
Want all the latest pregnancy and birth announcements, plus celebrity mom blogs? Click here to get those and more in the PEOPLE Babies newsletter.
RELATED VIDEO: James and Nicky Hilton Rothschild Expecting Second Child
The star is hoping that she’ll be getting a nephew this time around — “I hope it’s a boy,” she says — Hilton Rothschild, 34, and her husband already share daughter Lily-Grace Victoria, 15 months.
Either way, though, Hilton says her little sister is ready for baby No. 2. “She’s going to be amazing,” says Hilton, adding, “Lily-Grace actually just started walking, so that was amazing to get a video the other day of that. We’ve been waiting for that.Read more at PeopleTVwatch