Cecelia is about fifty or so in Jessi's Horrible Prank. She is not naturally thin.
Jessi says she always looks like she ate a lemon, with a sour expression on her face in Baby-sitters' Island Adventure and permanently pursed lips.
Cecelia was mentioned to play Harriet Tubman in a junior high school play when she was little in Happy Holidays, Jessi. In the same book she was in a minor car accident and only suffered from cuts and bruises.
In Baby-sitters' Island Adventure, Jessi calls her to help with Squirt when Becca goes missing during a boating race.
In Jessi's Baby-sitter, she moves in with the Ramseys to help take care of the house and kids after Jessi's mother, Janice Ramsey goes back to work. Both Becca and Jessi pulls pranks on her but she pretends that it doesn't bother her. By the end of the book she gets back at them after sitting down to talk. Cecelia lived in Oakley, New Jersey until her husband, Steven passed away and she moved to Queenstown, Connecticut. At first, Aunt Cecelia was strict with Jessi and Becca which causes the girls to play pranks on her. After a family meeting, Cecelia says that she was worried that she wouldn't be as good of a sitter as Jessi and that she only wants the girls to grow up well.
Cecelia has a son named Michael Parker, who lives in Brooklyn, New York with his wife, Marian. She does not always get along with him, but pushed him to follow his dream of being an artist in Jessi's Big Break.
She is very supportive of Jessi's pursuit of ballet. She wears thick, smelly perfume and her lips are constantly pursed (according to Jessi). She drives a Volkswagen and has a friend named Mr. Major. In Jessi and the Troublemaker, Jessi and Becca thought that Cecelia and Mr. Major were getting married, but they're not.
In Happy Holidays, Jessi, she got in a car accident. Her neck got injured from whiplash and she sprained her ankle.
In Stacey and the Fashion Victim, she occassionally smokes sometimes but she never does it in public. She participated in the Stoneybrook Smokeout, organized by the BSC. Cecelia had signed a pledge in front of Jessi and Becca.
- She wanted to be an actress when she was young as mentioned in Jessi's Big Break, but life had a way of beating her down.
- Cecelia appreciates the arts in Jessi's Big Break.
- She irons everything including underwear according to Jessi in Mallory Hates Boys (and Gym).
- Cecelia has arthritis in her ankle in Happy Holidays, Jessi.