Cream is the young and kind hearted freedom fighter. Though not the most experienced in fighting, or much of life in general due to her small status, she more than makes up for it with her abilities of flight, usage of Cheese the Chao her companion, and willingness to try her best at anything she does. She's extremely well mannered, usually referring to people as Mr. Or Mrs. , and always listens to her mother Vanilla who's just as kind hearted. Though on the outside she seems small and weak, just as Tails, she is far more powerful than she lets on, being just as capable of taking down Eggmans machines as stronger freedom fighters.

Cream is a smaller and soft-spoken individual, and her voice should carry this same sound. Rebecca Honig is the preferred sound you should go for in this audition. Here's a video for reference. 

https://www.youtube.com/watch?v=ObksBPSzQtw