Asking for a First and Last House Cleaning Charge?

I clean houses and am wondering if anyone charges clients a "first and last cleaning"?

Meaning if someone cancels, last minute or day of, then you have that last payment in order to give yourself enough time to find a new client to replace them.

I've had clients just cancel and say. "I can't afford you", or "something came up".

But no thought is given to really give any notice or consider how it affects the cleaner when it is a sole income to make a living.

Is this fair to ask of clients? Or asking too much?