Parents: Connie and Steve Sigler.
Has two older brothers, Brian and Adam (1973-November 12, 2014 - he died after slipping into a coma following a massive brain hemorrhage).
Accepted to NYU, planning to major in psychology. 
Has appeared in several off-Broadway productions including "Annie" and "Anne Frank".
Appeared in an episode of The Oprah Winfrey Show (1986) where she discussed how she almost became anorexic after her boyfriend broke up with her.
Attended Jericho Senior High School in Jericho, NY. Graduated in June 1999. Voted Class Thespian.
After the success of The Sopranos (1999), she dropped out from NYU in November 1999 to pursue her show business career. She has not ruled out returning to college one day.
Originally, HBO wanted to replace Sigler in The Sopranos (1999) with a blonde after the first four episodes, but it was deemed too expensive to reshoot all of those scenes.
MTV premiered the video for her song "Cry Baby" on Total Request Live (1998).
Jamie-Lynn's father, Steve Sigler, is president of an amateur baseball league.
Sang "The Star-Spangled Banner" at the inaugural game--specifically a Major League Soccer game between the New England Revolution and the Dallas Burn--at CMGI Field in Foxboro, Massachusetts on May 11, 2002.
Sang "O, Canada" and "The Star Spangled Banner" before game six of the first round of the NHL playoffs in 2002. (New York Islanders vs. Toronto Maple Leafs).
[September 2002] Announced engagement to her former manager, A.J. Discala.
Married her manager at the Brooklyn Botanic Garden in New York.
Wedding guest Carly Simon sang "Nobody Does It Better," "My Romance," and "Moon River".
Her wedding was featured in the February 2004 issue of InStyle Magazine, and also on the ABC special, Celebrity Weddings: In Style (2006).
Her ex-husband is Italian-American.
Battled an eating disorder in the late 1990s while starring on The Sopranos (1999).
Ranked #73 in Stuff magazine's "102 Sexiest Women In The World" (2002)
Good friends with Jessica Simpson and Lance Bass.
Her mother, Consuela (Lopez), a Cuban immigrant, is a convert to Judaism. Her father, Steve Sigler, is of Romanian Jewish, Greek Jewish, and Albanian Jewish descent (Ashkenazi and Sephardi).
Speaks fluent Greek and Spanish.
September 2005: announced that she & her husband, A.J. Discala, have separated.
Named #42 in FHM's "100 Sexiest Women in the World 2005" special supplement. (2005)
Was featured as #24 in Maxim Magazine's "Hot 100 of 2002" supplement. (2002)
Ranked #59 on the Maxim magazine Hot 100 of 2007 list.
She was February on FHM magazine's 2005 pin-up calendar (2005).
Broke up with Jerry Ferrara [December 22, 2009].
Was diagnosed with multiple sclerosis in 2001 at the age 20 but only revealed it 15 years later on January 20, 2016.
(January 16, 2016) Married her boyfriend of nearly 4 years Cutter Dykstra, son of Lenny Dykstra, in Palm Springs, California. Former *NSYNC member, Lance Bass, officiated the ceremony. They have 2-year-old son Beau together.
Has two sons with her husband Cutter Dykstra - Beau Kyle Dykstra (b. August 28, 2013) and Jack Adam Dykstra (b. January 15, 2018). Jack's middle name is in honor of her late brother Adam.