I lost my original comment I was typing as my device died so I’ll keep it short. Your aunt extracts money from people on the basis of owning private property (private property is property that is owned by an individual for non-personal use). She doesn’t earn the money through her own labour, she gets it by owning an asset that she herself has no use for and someone else needs and charges that person for using it. This is a parasitic relationship. Now to answer your question about if she is a bad person because of it, I would say not necessarily. The fact that landlords exist is a bad thing. We live in a system however where investment in private property (something inherently parasitic) is often the only way to retire. Every working Australian is required by law to invest a portion of their pay into an investment fund. This too is parasitic. That doesn’t however make every working Australian a bad person, they are just working within the system and doing what is required of them to live. Another thing to keep in mind is that for every house that is owned as an investment property, the price to buy a house goes up. By being a landlord, you make it harder for others to own a home.
So your issue is that owning a house is too expensive because housing is artificially scarce but you don’t think that privately owned investment properties is the fault of that? Renting will always cost more than the upkeep of a house because otherwise nobody would lease. The only reasons housing prices changing is a worry to homeowners is because housing is artificially scarce and the artificial scarcity changes based on how much of the artificially scarce housing investors decide to put on the market. All your issues with personal ownership of a house stem from other people treating housing as private property that can be invested in.