Answer:
Janet is watching a virus.
Step-by-step explanation:
Viruses are tiny beings, measuring about 0.1µm in diameter, with dimensions only observable under the electron microscope. Basically they consist of only one nucleic acid, which can be DNA or RNA, surrounded by a protein coat called capsid, which besides protecting the genetic material, chemically combines with membrane receptors of parasitized cells.
Since the creature Janet is observing under the microscope has only RNA, we can say that she is observing a virus.