If she does legitimate work for the business then she could be employed with super etc. Having her invoice your company (She would need an ABN) runs the risk that the ATO consider her an employee rather than contractor – so you will get hit with fail to withhold penalty which is significant and based on the gross amount paid. Final option is that the shares in the company are owned by a discretionary trust but transferring them now might trigger CGT depending on the value of the company. And of course you have extra compliance costs which is not ideal. The final option would be best if you thought there would be ongoing opportunities with family beneficiaries.
The only other thing to consider is just make sure your company is not subject to PSI because it will invalidate income splitting and assess all to you.