The former Lizzie McGuire looked like she'd come from the gym in her leggings and trainers as she walked hand-in-hand with little Luca in Sherman Oaks, Los Angeles on Wednesday (14 August).
Hilary had begun her morning by sending an anniversary message to husband Mike Comrie, tweeting: "3 yrs ago today I married a wonderful man! So lucky we found each other. He also gave me the most precious boy I ever layed my eyes on!!."
Their son Luca was born in 2012.
Earlier this summer, Hilary tweeted about her son: "The TOTAL and ABSOLUTE love of me and Mikes life."
Hilary told E! News last week that little Luca has been "talking a lot" lately – not that she understands everything he says.
"He looks at me like, 'Uh, didn't you get that?' And I'm like, 'Uh, Luc, I don't speak that yet,'" she said. "I think he's confused as to who's learning the language here. He's trying to teach me his."