It's okay. I don't think your feet are ugly at all I am a girl, too. One of my classmates also said that her feet were ugly, but she still wore sandals barefoot. You don't have to be shy to wear sandals. People won't care if your feet look bad, but you are comfortable. If you wear sandals and others talk about you behind your back, you don't have to care. Like me, my feet are not very nice. My classmates and I went out to mend our feet to make them look better before wearing sandals.