S.B.
When my daugher was about 1 1/2, her favorite food was bread and butter. That's all she wanted. I could usually coax her into something else.
At the same time, the only thing my older daughter wanted to eat was pizza.
Children go through food phases, just like they go through other stages. I wouldn't worry too much. As long as she is eating.
The most you can do is try new things. Maybe you could try fruit smoothies or something.