Ask your pediatrician if she knows any other physicians you can shadow. Physicians tend to know one another.
Some hospitals have formal shadowing programs. Look at every hospital within 20 miles and see if they have such a program. Some smaller hospitals also tend to have volunteer offices that are nice enough to lowkey hook you up with a physician.
Try cold calling physicians and ask if you can shadow for a few hours. It might take 200 calls but you'll eventually find a nice enough physician. Once you get in for a few hours, you can then ask to come back again for more. This method is extremely inefficient, but it is the only option for many applicants.
Find any private practices near your home and see if you can shadow the physician there. After your first visit, you can ask to come back for more hours. You can also ask if they know other types of physicians.
If you have any friends or family that have physician parents, ask if you can shadow them.
The hardest part is getting your foot in the door. After that, it's all about making connections and networking.