Isaiah clocks in some mother-son time at the gym, where the toddler can be seen working on his yoga moves with mom Carrie.
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Isaiah may not have made it to New Zealand with his famous mom, but he sure did try — as evidenced by this cute snap.
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Bring on the belly rubs! "I half expected these two to clash, but with lots of carefully watched playtime and working hard to teach both how to treat each other, we've managed to do alright!" Underwood wrote of her son and dog Penny's relationship. "I even think they might [heart] each other!"
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Isaiah runs around the park while the Grammy winner documents the sweet moment.
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CUDDLE & CURL
The famous mom has definitely mastered multitasking. "He doesn't care that Mommy had to get ready for a show...all he knows is that he woke up cranky from his nap and needed a cuddle...and I was more than happy to comply," she captioned a dressing room photo.
"He soaks in the sunshine … and I realize that he is mine … I don't deserve such sweetness," Underwood, 34, captioned a photo of Isaiah laughing, which she posted to her Instagram.
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At seven months old, Isaiah played with his toys while wearing a pumpkin-esque mask.
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Seen here flipping through a picture book, Underwood and Fisher's little one sported a gingham print shirt to tackle on reading time.
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Although this photo finds Underwood and her son on a rare getaway, it doesn't compare to the dream vacation the singer has in mind for her son. "I want to take him to Disney World when he's 5," she says.
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A CANDID MOMENT
"[Mike] is a great dad," the country star told PEOPLE. "My trust in him has only gotten deeper."
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LIKE MOTHER, LIKE SON
Isaiah took a turn at a baby piano, proving that his Grammy-winning mom's penchant for music definitely runs in the family.
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STEP BY STEP
"I don't think Mike would be like, 'We failed!' if he doesn't play hockey," Underwood told PEOPLE of her son, pictured here wearing his dad's hockey jersey.
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Isaiah squeezed in a much-needed nap session by a window.
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MOMMY & ME
"Right now he's such a blank canvas," the singer told PEOPLE of Isaiah.