If I were you I would focus on getting stronger, what type of strength program are you running? The side affect of getting stronger is that you should be able maintain a similar body weight whilst looking more athletic and dropping a couple of points of body fat - though 21% is a pretty healthy level for females.
So how to eat? You could try playing with cyclic low carb / high carb gig. So eat well and higher carb on your training days, and eat a little less and higher fat on non training days.
So as a rough guide and starting place on training days you may have 100 - 150g of carb and non training days around 50ish.