Not sure what I need to do

OK, so I have already lost all the weight that I want or need to, but now I want to lose fat. I am 5'3" and 115 lbs and I have 2 children aged 3 and 1. My issue is that I have an extra layer of fat and even though I have acquired a good bit of muscle through exercise I can't see it in some places such as my stomach. My exercise teacher told me it is my diet and that eating fried foods even on occasion was too much. I eat out twice a week and generally don't eat the fries, but I do eat nuggets and such. All the other tiems I cook at home and make almost everything from scratch. Is my only chance to see my muscles to give up sugar, flour, and dairy and be on a strict diet? I am confused and have done some searching on the internet only to be more confused. Thanks for any help you can give.