Gisele Bündchen shared an adorable photo of her 18-month-old son working out alongside her on a yacht. The Brazilian supermodel took to Instagram Friday to post a rare photo of the toddler, whose name hasn’t been revealed, mimicking her pose, with his tiny hands placed on two dumbbells and one leg lifted in the air. “It’s so sweet to see how little they are when they start watching and emulating what we do,” she captioned the snap. “They’re learning from us even when we don’t realize it,” Bündchen, 46, continued. “Moments like this remind me that my actions matter more than what I say, because so much of who they’re becoming is shaped by…