Because of her mother's teachings in the importance of manners, Cream is a princess-like figure; she is very polite and well-behaved,  speaks courteously (often referring to people as "Mr." and "Miss") and does what she is told. With her politeness being like second-nature to her, Cream acts out her teachings with a cheerful smile on her face and a soft voice. Regardless of the situation and being used to getting what she wants, Cream never forgets her manners, even offering a polite curtsy before attacking Eggman, with extreme prejudice.

While I'm being lenient on this, the voice I am looking for a voice similar to her actor, Michelle Ruff, here is an example of her voice work. (As well as the other actresses since Cream's voice is very samey)

https://www.youtube.com/watch?v=6o2SoERXxt0