The photos capture Lee carrying her son on her back as they ascended a 4,000-meter-high mountain in the Himalayas, as reported by The Korea Times.
A short video also shows the pair enjoying a snowball fight amid the mountainous landscape.
"We started preparing at 3 a.m. with plans to arrive early, but we couldn't move fast enough. Still, we made it to the 4,200-meter Mardi Himal viewpoint with everyone keeping pace," Lee wrote on Instagram.
"The weather was challenging throughout the trek, with rain and snow toward the end. But on the last day, it felt like a blessing to be welcomed by clear skies. I'm incredibly grateful and happy for every moment spent in the Himalayas," she added.
On Nov. 10, Lee updated fans that they had safely completed their trek.
On South Korean social media, many netizens praised her as a courageous and loving mother. However, some expressed concerns about their safety, pointing out that taking a 6-year-old into the harsh conditions of the Himalayas might be risky.
"Safe? Or a bit reckless?" one netizen questioned.
Lee, 42, has one son with her businessman husband. In 2023, she also hiked Mount Halla, carrying her son on her back.
The Himalayas is the world's highest mountain range that includes several peaks exceeding 8,000 meters in elevation, including Mount Everest, the highest mountain on Earth. The Himalaya form an arc 2,400 km long that separates the Indian subcontinent in the south from the Tibetan Plateau in the north, according to British adventure travel operator The Mountain Company.
Temperatures in the Himalayas drop by approximately 2 degrees Celsius for every 300-meter rise in altitude, with higher altitudes experiencing notably low temperatures. During winter, low-pressure systems from the west bring heavy snowfall to the region.