I believe the answer is: If she had purchased only the stock and had not diversified her investments, she would have lost money
Investing a stock market is a speculation game. Which means that you will never be 100% sure whether you will lose or gain money.
The best thing to do in this speculation game is to diversify your investment.
By doing this, if you somehow had to lose money, you would not lost all your investment and still had the chance to regain it.