ship station inventory need to add some option to make it perfect

parent SKU and child SKU need

i have a parent SKU (inventory is 100pcs), and child sku  A and B.

in amazon, when sold child SKU A, i need take off the inventory from parent SKU  10pcs, when sold child SKU B, need to take off the inventory from parent SKU 5pcs.

for now, shipstation can't do it, so my inventory always wrong.

hope ship station can help me out