Mommy-to-be was joined by sister Ashlee Simpson and Jessica Alba at L.A.-area party. By Jocelyn Vena Jessica Simpson With Jessica Simpson not far from her due date, the singer’s friends and family gathered over the weekend to celebrate her impending motherhood. Simpson celebrated on Sunday with other famous mamas like “Grey’s Anatomy” star Ellen Pompeo, Jessica Alba and little sister Ashlee, People reported. The party was held in Los Angeles and organized by celebrity party planner Mindy Weiss. “Jessica looked pretty and very happy,” an insider told the magazine. Another source added, “She’s so excited to be a mom. She can’t wait to meet her little girl.” Simpson recently revealed she and her fianc
