Ashlee Simpson and Evan Ross will say "I do" on Wednesday, August 31 Credit: Amy E. Price/Getty Images for SXSW

It's a nice weekend for a white wedding! Ashlee Simpson and Evan Ross are gearing up to say "I do," spending Labor Day Weekend on the East Coast with their famous families before their wedding on Sunday, Aug. 31. 

Sources tell Us Weekly exclusively that the couple will exchange vows in Greenwich, Conn. at the estate of Ross' mother, Diana Ross. The legendary Supremes singer, 70, was involved in the planning for the ceremony and may even be singing. 

Also scheduled to perform is another icon, Stevie Wonder, who will be making an appearance at both the ceremony and the reception. 

Simpson, 29, will be walked down the aisle by Bronx, her 5-year-old son with ex-husband Pete Wentz, sources tell Us. She will be wearing a pearl-embellished wedding dress and is set to be sparkling in $750,000 of Neil Lane rubies and diamonds. 

The "L.O.V.E." singer's style will be reflected in the festivities, as insiders tell Us that the evening will have a Bohemian theme, complete with dream catchers, eclectic touches, and a mix-and-match palette. 

It will be a family affair for both the bride and groom. In addition to Ross' mother in the ceremony, his half-sister Tracee Ellis Ross will be MCing the event. 

Simpson will be joined by her sister Jessica Simpson, who is the matron of honor for the ceremony. Jessica's daughter Maxwell, 2, and son Ace, 14 months, will serve as flower girl and ring bearer, respectively, for their aunt's wedding. 

Recently wed Jessica, 34, will also have her namesake shoes in the swanky affair, as a source tells Us that the bridesmaids will be wearing Jessica Simpson heels. 

This will be the first marriage for The Hunger Games: Mockingjay actor Ross, 26. He proposed to Simpson this past January, after they began dating in early 2013. The bride was previously married for three years to Fall Out Boy rocker Wentz, filing for divorce in February 2011.