Pia is a German outside hitter and member of the German National Team. In 2025, she played for the Atlanta Vibe in the Pro Volleyball Federation (PVF), finishing 2nd in the regular season and 3rd in the playoffs. In 2024, she competed in the German Bundesliga with Dresden SC, helping the team secure a Bronze medal in the league playoffs. Timmer had a standout collegiate career at Washington State University from 2019 to 2023, where she became one of the most decorated players in program history. She holds the school record for career aces (152) and ranks 3rd in career kills (1,704), 2nd in career points (1,959.0), and 5th in kills per set (3.33). A consistent performer, she was a 4-time Pac-12 All-Conference First Team selection and earned 4 AVCA Pacific North All-Region honors. Timmer appeared in 509 sets across 141 matches, ranking top three all-time in both categories at WSU. She also holds single-match records, including most points in a match (39.0) and is tied for most aces in both a 3-set (6) and 5-set (5) match.