I don't think she would be optimally comfortable. :] Plus I won't even trust sand with a KSB because i know what it can do respiratory wise.
I have my first boa as well.. he is on paper towels with aspen on top (one side is higher so he could burrow if he wanted) but he loves to elevate under the red-heat lamp. They usually like to climb instead of hide!
Good for you. :]