Joanna "Jo" de la Vega is a legal aid attorney at Wethersby & Stone LLP. She is the daughter of an unnamed woman, the sister of the late Danny de la Vega and the best friend and former co-worker of the late Laurel Lance at the CNRI. She is also one of The Arrow's supporters.
At some point in law school, Joanna met and befriended Laurel Lance. After graduation, the two of them went on to work together at City Necessary Resources Initiative (CNRI), a legal aid office in The Glades.
Working at the CNRI
At CNRI, Joanna was discussing a case against Adam Hunt with Laurel when a breaking news report about Oliver Queen being found was broadcasted. It also mentioned Sara Lance's supposed fate, which caused Laurel to angrily turn off the TV, leaving Joanna concerned for her friend. Later, Joanna informed Laurel that Hunt's lawyers arranged for them to appear in front of Judge Grell, though Laurel remained optimistic. After The Hood distributed the money Adam Hunt stole back to its owners, Joanna and Laurel were ecstatic, with Joanna proudly declaring the vigilante to be Starling City's "guardian angel". She then told Laurel that Tommy Merlyn arrived to see her.
Joanna tried to get Laurel to loosen up by taking her to Max Fuller's club, Poison. She was also the one who convinced Laurel to allow Tommy to host a fundraiser for the office after their largest donor pulled out.
Joanna's brother Danny was killed on duty while putting out a fire. The fire department said that he died from exposure to fire, but she believed he was murdered, due to the fact that firefighter's suits are designed to withstand the heat and fire burns. After Garfield Lynns' death she moved back with her mother and while saying goodbye to Laurel she asked her to find a way to give Danny's fire badge to the Hood, as she viewed the vigilante as a guardian angel.
After several months, Joanna returned to work. That week after the Undertaking was announced, Joanna and her coworkers headed to CNRI during the evacuations to retrieve all their files and evidences from various cases for their clients. When the earthquake started, Joanna managed to escape CNRI while Laurel was trapped. After Tommy died saving Laurel from the collapsing building, Joanna, Quentin and Laurel sadly watched the destruction.
Helping a friend
Moving on to a private law firm, she met with Laurel about a possible job offer. She told Laurel that the firm could not hire her, as one of the firm's partners was aware that Laurel was being disbarred, and offered to help her fight the disbarment.
It can be assumed that Joanna attended Laurel's funeral, where the latter's identity as Black Canary was revealed.