Brinkley, whose court battle with architect Peter Cook is set to resume today, arrived with their daughter Alexa Joel, 20, to celebrate the holiday along with a dozen other guests.
She split from Joel in 1994 after nine years of marriage, but the pair stayed close, with Brinkley attending his wedding to culinary artist Katie Lee in 2004.
And now he has emerged as a source of comfort for the 54-year-old, with insiders revealing she spent the day 'blowing off some steam'.A source told People: 'It was just a relaxing little get-together. Nothing special. Just what everyone does on the Fourth.