Donald Trump may be in big trouble if he keeps mouthing off to the judge in the E. Jean Carroll defamation case, a lawyer told the former president’s niece in an interview published on Friday. Mary Trump said that her family member, the ex-president, had lobbed “personally attacks” at the judge presiding over the E. Jean Carroll trial. A lawyer purportedly told her that Trump could end up in jail. “Tonight, Donald’s attorneys have asked for a mistrial in the E. Jean Carroll case. It’s a gutsy—or desperate—move considering Judge Kaplan already declined their identical request last week,” Mary T…