Answer: She makes $58.50 in profit.
Explanation:
It costs $2.50 to make each bottle
She sells each bottle for $7
2.50 * 13 = 32.5
It costs her $32.50 to make all the bottles.
7 * 13 = 91
She sells them all for $91.
91 - 32.5 = 58.5
$58.50 is the profit.