Thank you for contacting us. There are a few main pathways your sister can follow to apply for Permanent Residency in Australia. She can apply directly if she can claim enough points for 189 Visa OR she could follow the Study pathway to PR (the most commonly used path) OR she could go for Family Sponsorship Visa 489 Visa. However due to DIBP's policy the first preference is given to 189 Visas for Invitations and then if seats are still available, it will go to 489 Invitations. You would have to consider your situation before making the final decision on how to approach PR.