Andrew Harnik / Getty Images President Donald Trump’s niece warned that her uncle’s apparent mental and physical decline may be only the beginning. In a conversation with journalist Steven Beschloss published in her newsletter on Sunday, Mary Trump agreed that her 80-year-old uncle’s visibly decaying health, as evidenced by his behavior at the G7 summit last week, can no longer be masked. Asked by Beschloss, 67, whether the president looks “unusually diminished,” Mary, 61, said that “I think thi