you can look at this in a couple of ways.
She bought the flower twice for a total of $(6+8)=$14
She sold it twice for a total of $(7+9)=$16
So her profit is $2
Or...... She buys it for $6, sells it for $7, making a profit of $1.
Then....She buys it again for $8 and sells it for $9, making another $1 profit.