Maryanne is extremely shy, embarrassed, and inexperienced (e.g., toothy blow job, yanks at it like she's shucking corn). Has no idea what a man wants. Stacked and firm as a bushel of fresh produce, though. And willing to learn. Submits meekly. Prolly comes but it's so quiet it's like hearing a mouse squeak.
Ginger is not shy at all. Knows just what she wants but couldn't care less about you. Selfish and jaded as all hell. Bossy and sarcastic in the sack, like having sex with a good looking Rosanne Arnold-- a "say my name *****" kinda girl. Built like a ship brickhouse though and if you do bring it off at least you'll have the satisfaction of hearing her sound off like the QE2 in heavy fog.
Mrs. Howell is a super freak. Nothing is too nasty. Her wrinkles have wrinkles so keep yer eyes shut tight and let your ears and body be the sensory organs. While like Ginger she wants what she wants, she's old enough to know giving is getting. She can make you come just using her pinkie. And while Ginger likes the dirty talk, Mrs Howell wrote the language. If you think you're not shy, Mrs. Howell will teach you otherwise.
I believe your assessment of Mary Ann is way off, but the other 2 you nailed (so to speak).
Mary Ann is either the eager to learn virgin who can't get enough after getting hooked, or the mid-western slut who has had so many rolls in the hay she sleeps with a horse blanket.