I've been working out and can tell my muscles are getting more defined but...?

i can't seem to burn the layer of fat on top. i've been watching what i eat and the proportions but i'm not on any particular diet (i.e. atkins, south beatch, etc.) just trying to eat a balanced healthy diet. any suggestions? oh and i had a baby 2 months ago. i'm trying to loose the weight i gained. i'm 5'2 and pre pregnancy i was 115lbs. now i'm around 130. i'd like to get down to 110. i'm done feeding too.