@MiamiDAP I agree with @romanigypsyeyes This may have been the strictures in place in your D’s experience but many schools exist that have little to no barriers in registering in a wide variety of classes.
To the OP: this shouldn’t worry you excessively at this point. When researching schools, simply ask how easy it is to take a good no. of courses outside your stated major. Some will heartily say YES. Some others won’t. There you go…