She lost $12.75 for taking 3 hours off without pay
Explanation:
If she makes $34 every 8 hours, that goes down to $4.25 per hour. If she took 3 hours off without pay, we simply would multiply her hourly rate of $4.25 by the amount of hours she took off without pay (3) and we'd get our answer of $12.75 or the amount she lost!