Thank you all for your responses. I'm waiting for my family to let me know if they're keeping the jewelry here or if they plan to travel back with it. I've been searching for more concrete info but there's very little, but most sites and experiences say they got hassled when trying to enter with gold jewelry and were told they needed to declare it if it's valued at over $10k and some were told they need to file the FinCEN 105. But we're still in the process of figuring out the value of what they have. It's weird that there's no explicit information pertaining to this.