Babysitter's last family owes her thousands of dollars for unpaid childcare. She can't find them to serve court papers. What's her best strategy?

My babysitter is a sweet young lady from Brazil. Unfortunately, her last family owes her roughly 15k in unpaid child care fees. She trusted them, and they took advantage. She is doing everything to find them, but they are trying to hide from being served court papers. One of them still actively posts on TikTok in expensive cars, and with luxury bags. It's all a big slap in face. Does anyone have any good ideas how to find these people to serve them a court summons?