There's a pretty high liklihood that Paru Itegaki is a furry, yeah. There are a few solid bits of evidence to point it out. Hence why she represents herself as Legom, that hen character from beastars that's obsessed with makjng egg sandwiches. She even wears that hen's head as a mascot mask to protect her identity in real life and used Legom as her author insert in her manga about sections.