Manhattan prosecutors investigating Donald Trump’s role in paying hush money to a porn star also have been examining a $150,000 payment to a former Playboy model who alleged that she had an affair with the former president, according to people familiar with the matter, raising the prospect that Mr. Trump could face charges connected to the silencing of both women. Manhattan District Attorney Alvin Bragg’s office has been presenting a grand jury with evidence of Mr. Trump’s involvement in a $130,000 payment to porn star Stormy Daniels since January. In those proceedings, the people said, Mr. Bragg’s prosecutors also have...