If you way of reasoning was valid how could your partner afford to be investing in shares if you are the only bread winner??
Create a family trust (discrectionary) can even distribute $1300 pa to your kids, nieces & nephews to reduce tax liability. Then distribute the profits at will to minimise tax liability. Cost c$700 to set up a trust and your sailing. Can even distribute the franking credits in direct proportion to the profit but losses can be distributed.