Winning club Player of the Year in her first season, 1989–90, Mapes was also part of the Millwall team which won the 1991 Women's FA Cup when they defeated Doncaster Belles 1–0 at Prenton Park.
Before the end of the season, the first with a National league structure in England, Mapes was scouted by Swedish second-level club Lindsdals IF.
In 1994 Mapes was brought back to England by Croydon, whose player–manager Debbie Bampton was another member of Millwall's 1991 FA Cup winning team.
[3] Mapes converted her kick in the penalty shootout in the 1996 FA Women's Cup final win over Liverpool at the New Den.
In the 1997–98 FA Women's Cup Mapes took part in another semi–final shootout, this time as an emergency goalkeeper after Arsenal's Sarah Reed had been sent off.