Marceline was not in her full transformation yet. She was half wolf and half human right now as some of her body parts were covered by white fur but she was still in her human form.
She also noticed that her stab wounds were healed completely. She had been studying and researching werewolves so she was familiar with some of their powers and abilities.
She knew about the healing ability of the werewolf. With her current situation, realization had dawned on her. She recalled every detail of strange things happening to her for the past several years.
Her blackouts, her allergies, her extraordinary strength, her strange behavior during the full moon, and just recently, her super sense of smell and hearing– all of these led to one conclusion. She became a werewolf!
'NOOO! THIS COULDN'T BE! I don't want to become one of them! I loathe werewolves so much!'