Kathy Hiltonhas quickly become a fan favorite in her cameos onThe Real Housewives of Beverly Hillsthis season — but her youngest daughter,Nicky Hilton Rothschild, is shutting down the possibility that her mother will reach diamond status and join the cast permanently.

“I do not think she would,” Nicky, 37, tells PEOPLE of her mother while promoting the grand reopening ofSerendipity3on Friday. “I don’t think she has time for it. It’s a full time job.”

PEOPLE confirmed last October that Kathy, 62, would bejoining the Bravo franchisein its 11th season, which debuted in May. Kathy appears alongside sisterKyle Richards, who has been a part of the series since its 2010 debut. Kathy and Kyle’s other sister,Kim Richards, previously starred on the show’s first five seasons.

Vittorio Zunino Celotto/Getty

Nicky Hilton and Kathy Hilton

“I am watching,” she says. “I [was] absolutely hesitant because I watched the show and I know how drama-filled it is. But I like that she has managed to stay out of it for now. We’ll see!”

Nicole Weingart/Bravo

THE REAL HOUSEWIVES OF BEVERLY HILLS – “The Divided States of Erika” Episode 1105 – Pictured: (l-r) Lisa Rinna, Kathy Hilton, Sutton Stracke –

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Nicky is thrilled to see howRHOBHfans have positively responded to Kathy’s presence. “It’s so funny, I get tagged in memes all day and she barely knows what a meme is. So, I’ll send it to her,” she continues. “It’s pretty hilarious.”

Long before they were bonding overRHOBHmemes, Nicky and Kathy created cherished memories of visiting Serendipity3, beginning when she was a child.

The iconic N.Y.C. restaurant (which also sells several ice cream pint flavors, including Cookies & Cream Remix,online) officially opened its doors again on Friday after being closed for over a year due to renovations.

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Nicky Hilton

For Nicky, being a part of Serendipity3’s reopening event is a “very heartwarming and nostalgic and special” experience.

“I am a very proud born and bred New Yorker and Serendipity is an institution. I have been coming here my whole life,” Nicky, whose favorite item on the menu is the Frrrozen Hot Chocolate, tells PEOPLE “My mom always ordered the foot-long hot dog. Of course, we all have frozen hot chocolate during wintertime.”

source: people.com