You are showing loyalty to Woolworths. Woolworths Rewards doesn't reward loyalty, it rewards disloyalty. Have a separate membership for each adult member of the family and use a separate email address for each membership. Keep transactions as low as possible. If needed, do 2 transactions on one day, one where you swipe your card and one where you don't swipe your card. Give them the impression you are lowering your Woolworths spend and you might attract offers to get you to increase it. If they don't know what you really need each week, they might offer you a target which is easy to achieve. You may lose base points but played carefully you should eventually reap many more bonus points. Don't use a temporary unregistered card, you can't take up most of the good aspects of the program with an unregistered card.
Good luck.