Judy is a very caring and loving mother towards Jimmy and is very affectionate towards Hugh. However, she gets frustrated with Jimmy's antics and all the trouble he causes, usually having to give him a lecture or put him in his place. Sometimes, it is hinted that Jimmy may have gotten his super intelligence from his mother, such as in See Jimmy Run. She is best friends with Carl, Cindy, Libby, Nick and Brittany's mothers.
Judy's also the family mechanic—she can often be found in the garage, checking the plugs and points or adding horsepower to the family roadster. She may rule the Neutron house with an iron(ing) fist, but Judy does have a soft spot for her little Boy Genius. Unlike Hugh's mother, Granny Neutron, Judy's parents are never shown in the TV series.
Judy is a tall, skinny, and beautiful 50's housewife style woman. She has brown hair in a 50's style hairdo and green eyes with green eye shadow. She wears large gold hoop earrings and a white pearl necklace. She also wears a green sleeveless dress with small pink polka dots, green high-heel dress shoes, and rosy lipstick. She has a mole on the left side of her face. Her nails are polished with pink nail polish.
- "JAMES ISAAC NEUTRON!" - Judy's catchphrase
- "I am never leaving you two alone again! Humph!" -My Son, the Hamster
- "Hugh, do you ever realize that a lot of the things you say make NO sense??" -The League of Villains
- "But wouldn't the combustion cycle become increasingly irregular due to the inhibiting effects of the silicon's thermal resistance?" -See Jimmy Run
- "Hugh! Need anything from the store?" -The Eggpire Strikes Back
- "Hugh! Where did you get that thing??" -Sorry, Wrong Era
- Well... Okay, you can have one cookie. -Cookie Time
- "Now you GOTTA admit, that is pretty neat!!" (laughs with her family) -Jimmy Neutron: Boy Genius
- "Hugh Neutron, you buy our son back this instant!!" -Birth of a Salesman
- "James Isaac Neutron, what's been going on around here?!" -Return of the Nanobots
- "Chores first! Space travel later." -Send in the Clones
- "HUGH! STAY!" -Men at Work
- "Do I know you!?" -Jimmy Timmy Power Hour 3: The Jerkinators!
- "Hugh that was not our son! That thing had fur with big teeth and whiskers!" -My Son, the Hamster
- "Hugh that's Poultra's water dish!" -The Eggpire Strikes Back
- "Not Pizza Clown too!" -Men at Work
- "There invitations Hugh." -The Eggpire Strikes Back
- "Hi boys, there are fudge nellies in the kitchen." -Crime Sheen Investigation
- "Jimmy, I never want to hear you say the word Carl again!" -The Feud
- "Oh Hugh their taking Jimmy!" -The League of Villains
- "Jimmy! My sweet baby! What is he doing there!?" -Win Lose and Kaboom!
- "Cindy, Libby, have some cake and goody bags!" -Hypno-Birthday To You
- "Oh Jimmy you poor baby your as sick as a dog!" -Journey to the Center of Carl
- "Oh my! The same things happening to me too, and Goddard!" -The Trouble with Clones
- "James Neutron, go to bed right now and I mean you! Not the Jimmy Android that says nice things!" -Krunch Time
- "Hugh, you can't just invent a new holiday." -Holly Jolly Jimmy
- Judy is hypnotized by others many times throughout the series. Most notably, in the Jimmy Timmy Power Hour, she is deeply hypnotized by Timmy into thinking she is Mighty Mom. She stays in this hypnotically-brainwashed state for the entirety of the program and is never seen returning to her normal state.
- Judy's catchphrase is "James Isaac Neutron!"
- In the movie and the pilot, Judy sometimes wore a white apron.
- In Sheen's Brain, Judy could be seen in the background when Sheen comes into town with his new brain powers.