Prematurely health conscious

Recently, I noticed that Sarah is more interested in munching crackers than regular biscuits, and then she also has cornflakes, fruits like watermelon and apple and sometimes oats in small quantities. She would maximum have two bites of chappathi with dal and maybe two tablespoons of rice a day. I keep trying to feed her whatever we prepare at home but at vain. However, i take care not to force feed because she might develop a permanent aversion to food. She takes a mouthful and just nods her head saying NO. She also loves lemon juice. She is not a chubby and overweight; her weight is normal according to her age. Overall, when I look at what she has, she seems to be on a diet to loose weight. However, she loves chips and french fries but I have tried not to make it a habit else I might end up as those moms at malls - whose shopping trolleys are usually filled with colorful chips packets and tetra packs.