Lizzy was born on July 3, 2012. She is the second youngest child of Lynn R. Loud and Rita Loud and a member of the socially prominent Loud family. Her most annoying habit is her weird studies on others. She is often seen working on complex equations, experiments, or formulas. Along with Lacey, she's the quietest out of all the old money Loud siblings.
Lizzy had already finished school despite at a very young age, having finished school and getting a PhD. She is also a Nobel prize recipient.
Lizzy is also a child prodigy like her eighth cousin, Lisa, and is often egocentric and sarcastic with other people. She also speaks in a lateral lisp and has a stoic frown, and she also smiles from time to time. She is a devout Catholic and deeply religious and states that she only believes in Science, God, Jesus Christ, and the Holy Spirit. She can be very strict with her views. unlike her eighth cousin, she is one of the most mature of the Loud siblings and is above some of the childish plays herself, such as food fights. She also studies poop and her siblings bathroom habits, all of which her siblings find annoying. Unlike her said distant relative also, Lizzy is not scatterbrained at all, she never forgets any ingredients for her experiments, and always remembers where to place her vials, test tubes, and chemicals.
Like Lisa, Lizzy has short shaggy brown hair, and wears large glasses to help her see, she wears a dark red turtleneck sweater, light red pants, and brown shoes that all droop down to represent her stoic demeanor. Unlike her distant relative Lisa however, Lizzy wears a gold necklace with a gold cross, illustrating her faith in God.