Fliss Gibbons joined Albion in August 2017 for her second spell at the club.
During her first spell in 2014/15 she was named Player of the Year, scoring ten goals in 17 league appearances.
After leaving the Seagulls in 2015, she joined Millwall Lionesses for a year, before signing for Gillingham at the start of the 2016/17 season.
She broke a goalscoring record at the Kent club, scoring an incredible 33 goals in 19 appearances in the FA Women's Premier League Southern Division One.
The 27-year-old has been used more as a full-back during her second Albion spell, making 17 appearances in all competitions during the 2020/21 campaign.
Four Albion women's players to depart
Aileen Whelan, Fliss Gibbons, Dani Bowman and Emily Simpkins have made more than 200 Albion appearances between them.
Playing in a Wembley final would be amazing, says Gibbons
Defender says Albion are capable of producing an FA Cup shock against Arsenal.
Gibbons: We're so pleased for Lee
Striker's double meant so much to her Albion team-mates.
Gibbons: We're over the moon with result
Fliss Gibbons starred as Albion made it five wins from six games in the WSL.
Gibbons: Rainbow Laces display showcases club's support
Albion's teams across the club have been proudly supporting Stonewall's campaign this month.