K.J.
If she isn't losing weight and is still healthy, I wouldn't worry about it. If she is acting normal other than her eating, she probably just doesn't need much food. Toddlers slow their eating, because they don't grow as quickly as they did before. When she is hungry or needs nutrients, she will eat. The best thing you can do is keep offering her healthy food.
Another thing to consider is that she may just be a grazer. My 15 month old is like that. She will rarely sit down and eat a full meal, but she will eat little bits of food here and there throughout the day. You can also try that and see if she eats more over the day.