What happens if you give a Destiny Knot to a female pokemon?

This information provides a correct and detailed answer in relation to how the Destiny Knot works with breeding:

When you breed, you have 3 possibilities for the IV of each stat for the baby. The first is that the child will have the mother's IV for that stat, the second is that it will have the father's, and the third is that it will randomly choose an IV for that stat. When breeding without the knot, three of the IVs will be inherited from the parents. So if you have a set of 6 IV parents, the child might inherit the HP and Def from the mother and the Sp. Atk from the father, resulting in a 31/x/31/31/x/x child. With the destiny knot, five are passed down instead of three. In the example, we might inherit the Sp. Def and Speed from the father as well, resulting in a 31/x/31/31/31/31 child.

They don't pool. If a stat is passed down, it goes to that same stat, i.e. if the mother's HP is passed down, the child's HP will match the mother's. It won't go to a different stat or be added to a total amount to be distributed between stats.