My 7yo daughter fell from her bicycle last week and simply refuses to get on again. How do I convince her that it's okay to ride the bike again?

You give her sometime. Do not push her into taking it up too soon, but at the same time do not let a whole lot time pass. As if you will give her more time, the fear may settle in. I have experienced it with my son. Once, he was on a slide in the park and was pretty scared to come down, and I was helping him by holding his arm and making him slide. One day, my husband too accompanied us and seeing this, he told my son that you slide on your own and mamma is not going to hold you but I am here at the bottom for you. My son was reluctant in the beginning but my husband held him in his arms, and affirmatively asked him that do you trust papa? He said, "Yes." And then my husband build that trust in him and make him slide on his own. Trust that when he did it, he felt so proud of himself. So, all I want to say is build that trust in your daughter that nothing will happen and that you are there with her. And initially help her cycle, if need be put support wheels at the back and one by one remove them. Your support and confidence will in turn boost her confidence. Do not show that you are scared of her doing a particular turn on the cycle or the way she rides. Guide her, and she will soon catch up and overcome her fear.