It seems that you are referring to a previous calculation (Part A) that involves determining an area in square feet, which is not provided in your message.
To find out how much money Isabella's mother made, you would multiply the area in square feet (from Part A) by $3:
\[ \text{Total money made} = \text{Area (in square feet)} \times 3 \]
If you can provide the area from Part A, I can help you with the calculation.