I cant really tell you because i dont know for how long she intends to invest the money.

But A = P(1 + r/100)^n

If she wants $15 000 annually for 10 years, we can assume she wants $150 000 at the end of the investment period.

So 150 000 = P(1 + 11/100)^n

And then we can say thatP = (n-root(150 000)) / 1,11

P is the initial amount invested