How's them dog nails? To long for comfort on sidewalks? Maybe she burnt her paws on the sidewalk when she was younger. If that is the case I wouldn't force her onto the sidewalk. Maybe sit down or lay down on the sidewalk or next to it. Slowing bringing her to comfort with the sidewalk. Would take a lot more than just this but it would be a start in the right direction. Another thing to do is really pay attention to her expression when she does interact with the sidewalk. What do you think she's thinking? When have you seen these kinds of look on her face, in her body language. How does she respond then? How did you comfort her? Then use those experiences and memories and apply it to this sidewalk situation. Just keep in mind it will take time and trust to comfort a dog from a fear or discomfort.
If all that is to much for you, well then the extreme method is controversial but practiced by the professionals when needed . Take away her water. If she wants water, at the end she has to step on the sidewalk. Keep in mind this is a very unsafe practice and even basic Google information will have it wrong. Dehydration is very bad for dogs, especially in heat. It kills brain cells, or worst the dog. It can also mess up there mindset when they drink or want water. Etc. Like I said this is an extreme method, but I have seen it been used by professionals.
In honesty I would have some comfort in knowing my puppers doesn't want to go into the street. Always sad when one gets lost or hit. So I think a change in diet, more toys in the house to exercise with, and a clear path around the yard she can learn to do laps with... You both be good.