Nepeta is very patient - her moirallegiance with Equius, one of the destructive trolls of the twelve, should be the most obvious example of this, but the fact she continued to be Aradia's server player, despite not having any idea what's going on, could be another.
She is outwardly very exuberant, and will almost always let other people know how she is feeling, as seen with interactions with her pushy moirail, but when it comes to matters of the heart, she is much more reserved. Her shipping wall is very private - hiding it in a room where presumably no-one goes. She is scared easily and is actually creeped out by Equius' perspiration problems, opting not to take her favourite hat back when he uses it to wipe off sweat, and also is too afraid to tell Karkat how she feels about him, despite how devoted she is to shipping. She also seemed intimidated by Rose when asking to talk to Jaspersprite.
Despite looking cute, she is actually very deadly. She hunted wild animals to use their fur as flooring and blood to draw on the walls, and attempted to take down Gamzee, something which no-one else has done.