Bossman split a pair of doubles matches as her team finished pool play 3-0 with three consecutive 3-2 victories.
Saturday, the Mid-Atlantic Section representatives defeated teams from the New England and Southwest sections. That followed their triumph Friday against Northern California.
The Virginia Beach team will play a semifinal Sunday against Southern California, while the other semi pits Florida against the Caribbean. The winners will come back soon afterward to play for the championship, and the losing semifinalists will duel for third place.
Bossman and Tracy Johnson won 6-3, 6-2 at No. 1 doubles against New England, but Bossman and Cecilia Schulz lost 5-7, 6-1, 6-0 at No. 2 doubles against their Southwest opponents.