Image source, Getty Images Image caption, Naomi Girma (left) is now the most expensive women's footballer Emily Salley BBC Sport journalist Emma Sanders BBC Sport women’s football news reporter It has been one of the biggest Women's Super League transfer windows in history - but what impact will Chelsea's spending have? The WSL leaders have invested in their women's team and are reaping the rewards, picking up five successive league titles and competing in the Champions League. They have strengthened even more in January, bringing in USA defender Naomi Girma for a world-record fee, and adding England midfielder Keira Walsh from Barcelona in another big-money move. Chelsea 'win' the transfer window Image source, Getty Images Image caption, Girma won Olympic gold with the United States in Paris Chelsea's rivals will not be pleased at how successful a window the club have had. Not only have Chelsea added two world-class players to their ranks, they h...