cancellation fee for babysitter?

[kristine_elen]

We've hired a babysitter for tomorrow night but now it looks like we're all sick and so my husband and I won't be able to go out. I feel bad cancelling on the sitter (whom we've only hired once before). Should I offer her a cancellation fee, or is this just the way the cookie crumbles? The world of sitters is new to us.
Thanks.
(Posted on baby board, too, then realized parents of older babies might have more experience in this area.)