Federal authorities are continuing their investigation into the sudden death of 18-year-old Anna Kepner aboard a Carnival cruise ship — and now they’re zeroing in on a minor for possible criminal charges, according to ABC News.

The new development comes after Kepner’s stepmom, Shauntel Hudson, recently filed a request to delay her court hearing in a custody case unrelated to the FBI probe into Anna’s death, ABC reports, citing court documents.

In the family court filing … Hudson states she’s been informed by FBI investigators and her attorneys a “criminal case may be initiated against one of the minor children of this instant action.”

She also says any written or oral testimony she may give “could be prejudicial to her or her adolescent child in this pending criminal investigation,” and therefore she “cannot be compelled to testify.”

Hudson was on the Carnival Horizon cruise ship with her kids and Kepner’s dad when her stepdaughter’s body was found on November 8. The ship had left Miami enroute to the Caribbean, but was forced to return to Miami after the heartbreaking discovery.