It was Day 2 of the Ambani wedding in July, and Julia Hackman Chafé, a social media influencer who works in her family’s wholesale gemstone business in New York City, was on the verge of blacking out — or at least she thought she was.

Ms. Chafé, 25, and her husband, Bruno Chafé, were in Mumbai, India, as the guests of Anant Ambani, the younger son of India’s richest man, and Radhika Merchant, his longtime girlfriend, who were marrying in a spectacle of wealth and celebrity that had captured the world’s attention.

But it wasn’t the heat or the crowds that had pushed Ms. Chafé to the edge. It was an unexpected meeting with Kim Kardashian, one of her idols, who also was at the wedding. According to the anecdote Ms. Chafé shared the following morning on her social channels, where she covers the intersection of jewelry and pop culture, the first thing Ms. Kardashian said to her after being introduced was, “‘Oh my God, I totally watch all of your stuff.’”

Weeks later, Ms. Chafé described the effects of the encounter on a video call from her office in Midtown Manhattan, where she manages social media content for Intercolor USA: “I couldn’t see straight after she said that. My tongue was falling out of my mouth. My eyeballs were no longer in my face.”

In her own mind, Ms. Chafé may have been incapacitated. On social media, however, she was on fire.

During her six days in Mumbai, Ms. Chafé — who had scored an invite through an Ambani family friend she knew on Instagram — nearly doubled her Instagram followers to 639,000 from a pre-Ambani level of 337,000. Across all of her platforms combined, including TikTok and YouTube, she now has nearly a million followers.