She didn't. There is no such, "problematic 'gap' between the "knower and thing known." In fact, the, "knower," is as much a, "thing known," as any other thing. There is no, "gap," it is the invention of the mystic schoolmen.
It also confuses the real question which is how do we know anything, or epistemology. That Ayn Rand addressed very well.
Hank
Your proclamation doesn't solve the problem.
Rand contends that some chemicals in the brain ("thoughts") correspond to an external reality. The problem is this. How does she know that the chemicals in her brain correspond to an external reality? How could she possibly know?
There is, then, the obvious problem of knowing that our impressions are true representations of reality. There is no way to check them that does not itself rely on sensation and so is open to the same possibility of error. And since, on this view, one cannot tell if one's senses are delivering accurate information, one has reason to doubt that there is any referent for what one senses. One can reasonably (?) say that there is no extramental object (solipsism), or that there may or may not be an object, and we may or may not observe it accurately (relativism).