This is a bit pedantic, but I believe what you mean is that she understands that the problem is a few bad apples. The full phrase is "A few bad apples spoil the

This is a bit pedantic, but I believe what you mean is that she understands that the problem is a few bad apples. The full phrase is "A few bad apples spoil the bunch" — it only takes some minority threshold of underperformers to threaten the entire culture.