|Friend(s):||Nate Wright (boyfriend), Francis Pope, Teddy Ortiz, Dee Dee Holloway, Chad Applewhite|
|First Appearance:||Big Nate Blasts Off|
Upon moving into P.S. 38, Ruby Dinsmore was constantly chased down by two male students, Nate Wright and Randy Betancourt, who both had a crush on her. She gave Nate a can of soda pop when Artur Pashkov told her Nate was hungry, but when Randy shook it (something only witnessed by Drama Club President Dee Dee Holloway), the soda rocketed into Nate's face, shocking Ruby. Ruby eventually chose Nate; they got together when Martin Wright told Nate and his friends that they are not moving to California, which made an excited Ruby kiss Nate, breaking Randy. Apparently, Nate began to date Ruby. Randy waved her off, deciding that he could live without her.
Ruby Dinsmore is a new student, and she has a crush on Nate. Randy Betancourt has a crush on her, but she doesn't feel the same about him and is more compelled toward Wright. It is possible that she is one of his three girlfriends (alongside Kelly, Angie, and formerly, Trudy).
Randy Betancourt had a crush on Ruby Dinsmore, though Ruby does not feel the same way about him. In the end, Dinsmore chose Nate Wright and he waved her off.
Behind the scenes
She first appeared in Big Nate Blasts Off.