Could Boo be Andy's Mom?!

Boo, Disney Wiki

In Toy Story 3, one of the girls at the Sunnyside Daycare is a slightly older Boo from Monsters, Inc.

Boo from Monsters, Inc makes a cameo in Toy Story 4 - Look to the right of Bonnie in the background! : r/Pixar

Turning Red Theory Says Mei's Friend Is Secretly A Monsters Inc Character

bonnie toy story trend｜TikTok Search

51 Details In Pixar Movies That Confirm The Pixar Theory

Toy story and monster inc theory

Monsters, Inc. : Billy Crystal, John Goodman, Mary Gibbs, Steve Buscemi, James Coburn, Jennifer Tilly, Bob Peterson, John Ratzenberger, Frank Oz, Daniel Gerson, Steve Susskind, Bonnie Hunt, David Silverman, Lee Unkrich

Monsters University - Wikipedia

Pixar Easter Eggs