Hurdles exist for prosecution of each suspect: differing Statute of Limitations, differing national and international jurisdictions, evidence of a crime, including victim and witnesses.
In a nutshell: Maxwell was found guilty of sex trafficking:
Maxwell was sentenced to 20 years in prison for her role in a scheme to sexual exploit and abuse multiple minor girls with Jeffrey Epstein over the course of a decade. Maxwell was found guilty on December 29, 2021, following a one-month jury trial, of conspiracy to entice minors to travel to engage in illegal sex acts, conspiracy to transport minors to participate in illegal sex acts, transporting a minor to participate in illegal sex acts, sex trafficking conspiracy, and sex trafficking of a minor.
https://www.justice.gov/usao-sdny/pr/ghislaine-maxwell-sentenced-20-years-prison-conspiring-jeffrey-epstein-sexually-abuse