Gwen Stefani joined Twitter mid-afternoon Wednesday, and judging by her numerous posts, it seems she's already addicted to the social networking site!

Four hours after creating her own account, the No Doubt singer, 42, uploaded a series of fun photos from her youth. In one shot, the fresh-faced eighth grader poses next to her older brother Eric Stefani, now 44, "holding autographs of our favorite band, Madness."

Gwen -- mom to Kingston, 5, and Zuma, 3, and wife of Gavin Rossdale, 46 -- also shared a second photo of herself with Eric, who was once a member of No Doubt, taken in 1983. "I wish I still had that dress," the singer wrote.

Despite her multiple tweets, the "Hella Good" singer hasn't followed many people. At press time, she's only subscribed to No Doubt's official account, as well as bandmates Adrian Young, 42, Tom Dumont, 44, and Tony Kanal, 41.