With Black Lightning's ties to the original roster of the Outsiders, it's not surprising that he'd have a connection to the team when a new version was put together in 2003. In Outsiders #1, Judd Winick and Tom Raney introduced Anissa Pierce, alias Thunder, the oldest of Black Lightning's two daughters.
Like her father, Anissa's original costume involved a wig that helped to hide her identity, and like her father, she added some much-needed diversity to the DC Universe when it was revealed that she was in a romantic relationship with another member of the outsiders, Grace Choi. Her powers, however, are completely different. Rather than throwing lightning bolts around, Thunder can control her density, making her nearly invulnerable.
Oddly enough, Anissa's sister Jennifer both pre- and post-dates her, thanks to the weird quirks of superhero comics. A character meant to be Black Lightning's daughter appears in the non-canon 1998 Kingdom Come miniseries, by Mark Waid and Alex Ross, but is never identified in the comic itself, and is only referenced as "Black Lightning's metahuman daughter" in bonus material that appears in the paperback collection of the series. In 2008, though, thanks partially to Kingdom Come's enduring popularity, she was introduced to mainstream continuity as Anissa's younger sister, Jennifer.