Lopez, who shares 8-year-old twins Emme and Max with her ex-husband, Marc Anthony, moved next door to Chelsea and her husband, Marc Mezvinsky, in 2014, buying a $22 million penthouse at four-unit building The Whitman in New York City. Chelsea now has two kids of her own, 2-year-old Charlotte and 4-month-old Aidan.
The 47-year-old actress, who recently teamed up with Anthony for a free concert supporting Hillary, also opened up about why she's supporting the Democratic nominee for president.
"Our country deserves a great leader, not someone who dabbles in politics. I want someone who knows what they're doing," she said. "We deserve that and she has tremendous experience and tremendous heart and it takes a lot to be in the public eye, I know that."
"As women we get bullied, we have to work just a tiny bit harder, we have to show we're more qualified and I am with her," she added. "I do believe for this election she's the right person for the job."
While J.Lo and Chelsea have become close, they may no longer be neighbors if Hillary claims the White House.
ET caught up with Hillary and Chelsea in May, where Hillary revealed that she's planning to have a nursery for Chelsea's children at 1600 Pennsylvania Avenue.
"Oh my gosh, of course!" Hillary gushed. "Easy question! I am thrilled Charlotte recognizes me and calls me Grandma. I am thrilled that she'll occasionally ask her mother or father where I am and then, if I'm around, they'll FaceTime me."