She became the company's first celebrity ambassador and creative advisor.
The book "feature[s] personal stories and reflections on a range of topics that continue to define the contemporary landscape: sexuality, womanhood, friendship, race, marriage, and beauty." Union is a spokeswoman for Neutrogena. It was reported in November 2014 that Union became ambassador for nail polish company Sensatio Nail.She also appeared in Sister, Sister as Vanessa, in Smart Guy as Denise, and in five episodes of 7th Heaven as Keesha Hamilton.She also appeared on an episode of Friends, “The One with the Cheap Wedding Dress”, as Kristen, a love interest to both Ross & Joey. In the same year, she performed the role of Isis in the cheerleading movie Bring It On, opposite Kirsten Dunst. It led to Union being cast in the CBS television drama City of Angels as Dr. Union was featured in The Brothers and was seen as having a "beguiling sincerity, even when she's fudging the truth." Union was cast in her first leading role in the 2003 film Deliver Us from Eva with LL Cool J.She appeared in the 2005 film Neo Ned, costarring Jeremy Renner and portraying an African-American woman with delusions that she is Adolf Hitler.They were noted by Mark Olsen of the Los Angeles Times as having "a strange, offbeat chemistry that drives the film." Union starred in the short-lived ABC series Night Stalker.Her parents divorced after thirty years of marriage.
Union has said, "They handled their divorce and our subsequent transition into a blended family with grace and dignity and respect. I'm lucky that I can just mirror what my parents did and always put the kids first. I'm lucky." On her college football memories, Union reflected, "In my family if you couldn't talk Cornhusker football—that means knowing the black shirt defense, knowing the I-back formation—then you don't get to have an opinion.
When I first toured the Nebraska campus and I saw Turner Gill walk, I freaked out.
That was like the biggest star-struck moment I've probably ever had in my life.
In 2019 she joined the hit TV show America's Got Talent as a judge.
Union is also known for her performances in the romantic comedy films The Brothers (2001), Deliver Us from Eva (2003), Daddy's Little Girls (2007), Think Like a Man (2012) and Think Like a Man Too (2014).
This was her second time working with the rapper since making a cameo in his video "Paradise" in 2002.