Despite being a dog trainer, Cheri has the typical "alpha" personality. She is a rude, selfish, arrogant, nasty, abusive, greedy, controlling and manipulative woman. She is very self-serving, and abuses both people and animals. When she fails to control Stan, she tries to lie to and manipulate the family to get her way.
When Cheri was introduced, she's shown to be very rude. Cheri can be harsh to both dogs and people, as she once sprayed Ellen - who hired her in the first part.
Cheri is not afraid to say whats on her mind, as she proves to be rude towards others and claiming to be in "her house", showing somewhat how verbally abusive she is.
She's not afraid to yell at others as she demands to get what she wants, even inserting submissive to dogs.
Cheri also takes pride of herself being a dog trainer, however, when Stan, the first dog who never listens to her, loses confidence in herself, showing that no dog has ever resist her tactics.
She then selfishly tries to convince the family to take Stan away and tries to manipulate Ellen using her same tactics she uses on dogs. When she fails that, she storms out of the house in a tantrum and possibly lost her job.