We know that $97,600 was earned in one year. We also know that out of that total, $7,600 was a bonus. Since a bonus would not be included in the regular salary, you would want to subtract the bonus from the total.
The number you get is the amount of money earned in that year from the salary. Since there are 12 months in a year, you would divide that number by 12 to get the amount of money she earned each month.