I agree with massofmen's suggestion that Kerry is a "vanilla" actress, although this is based on her performances in BAT BOY, HAIRSPRAY, and LITTLE SHOP.
Perhaps my opinion would be changed by her turns in OPPOSITE OF SEX or EASTER RISING, as Rathnait and trash have mentioned.
Still, one cannot blame an actor for staying in a comfort zone - where they feel they will be successful - in as risky a venue as Broadway. In Kerry's case, this is mostly vanilla with a slightly corny, yet lovably zany side which is very appealing to the family audience and which has secured her an adoring fanbase.
"I am the sound of distant thunder, the color of flame."
CARRIE the Musical