Naru’s place with 〜んち

Grammar Explanation

美少女戦士セーラームーン » Kanzenban Release » Volume 1 » Page 13

A lunchtime conversation about recent jewelry store robberies gives way to talk about jewelry and the kinds Usagi and her friends would like to own.

「なるちゃんちでっかい宝石店(ほうせきてん)だよね。あたしルビーすきーっ♡ パールもいいなーっ」
“Naru‘s place is a huge jewelry store, isn’t it? (Me, I like rubies. Pearls are also nice.)”

「なるちゃんのうち」 is contracted into 「なるちゃんち」.