Home Affairs looks at whether you can realistically provide substantial and continuing care, not just whether you want to help.
Home Affairs may consider your general capacity to provide the care, the exact type and level of assistance needed, your understanding of the care needs, and your commitment to providing long-term assistance.
They may also consider your physical ability to provide care, whether you have tried to understand the person's condition, and how you and any accompanying family members plan to support yourselves financially.
If you have your own family commitments, Home Affairs may consider whether those commitments leave you able to provide the required care. Training, work experience or personal experience that helps you provide care may also be relevant.