Paul.
Of course it will, if it's not fixed in now, it certainly will be by then with traffic soiling on top too by the sounds of it.
Did you point out the limitations to the client, explain to her about what to do in future and take the opportunity to sell carpet protector?
You shouldn't need to leave it wet anyway. Dry it off completely after stain removal. Use an air mover.
Get on with it, earn some money out of it.