On September 12, 1998, Del Valle won a 10-round unanimous decision over Melinda Robinson to claim the vacant WIBF super featherweight title.

She fought and won six non-title bouts over the next 11 months, then defended her title against fellow unbeaten Lena Akesson on August 14, 1999, in Miami Beach, Florida.

Personal problems then kept her out of the ring for nearly a year before she challenged Laura Serrano on August 5, 2000, in Connecticut for the IBA version of the super featherweight title.

Over a three-month period in 2003, Del Valle challenged four of the top fighters in women's boxing, suffering her first three losses in the process.

Three weeks later, Del Valle moved back down to the super featherweight ranks once again and challenged Chevelle Hallback for her IBA title in Savannah, Georgia.

But she got back on the winning track on October 11, when she handed undefeated Kelli Cofer her first loss in a six-round fight in Greensboro, North Carolina.