A source close to the brunette beauty tells ET that she now refers to herself and Foxx as "we."
"They send each other voice memos, instead of text messages," the source says, noting that the two were in constant contact while Holmes was out and about in the Big Apple. "She was talking about him all day and gushing about how much fun she has with him."
A lot has changed for Holmes over the years. The typically low-key mother of one "used to attend things as an obligation," the source says, but appears to be having a lot more fun now.
"She'd do what she was responsible to do and then she'd leave. She was a homebody," the source explains. "It's great to see her out and having fun, and I bet Jamie has played a big part in that."
Before dating Foxx, Holmes was married to Tom Cruise for five years before calling it quits in 2012. They share one child together, 11-year-old daughter Suri.
"She stepped out of the spotlight to focus on her family and more indie projects like Broadway and small TV and movie roles," the source says. "She kept her circle really tight, but it's been years since the divorce and Katie deserves to be happy. She doesn't seem to care anymore who knows what's going on with her and Jamie. She's letting down her guard and being more open."