Mother-in-law waiting for government housing while living with us. Any other options?

My MIL lives with my boyfriend and I and she needs to move out - its not difficult to live with her or anything but we want out independence. Up until 2yrs ago, she was living on the road in a caravan with her husband whose now passed. She was unable to live that lifestyle without him so she sold the caravan and moved in with us. 18 months later, and her plan of moving out is 'waiting for government housing.' Shes going to need to be more proactive than that. Shes 18months from receiving the age pension and plans to work 20 or so hours a week for cash when that happens (insert ethical concerns here). She only has ~$70k and no super because it was already withdrawn when they sold their house, and she doesnt want to give up all her savings to purchase any kind of living space. She's lived an affluent lifestyle and made some cutbacks but not enough. My boyfriend and I will purchase a house in the next 6months and I dont mind if she lives on the property in a detached dwelling / caravan / granny flat, as long as she pays for it, but such oppurtunities that are already established are few and far between, and as I said, shes not going to part with her savings for it. Shes enquired to Bethany as well, but they have waiting lists of their own, and Im sure they'll take all her savings in a worse manner.

Are there any other options, because 'waiting for the government' doesn't cut it for me and theres no better time to act than now? Or who can we talk to about this?

EDIT: We're in WA. Thanks everyone, I agree with most of you. We'll seriously talk to her about buying a granny flat fully funded by her (if that means she needs a loan, then she needs to be ready for that - she's not retired yet and still fully able to work) and buy a larger plot to allow for this or to look at / advertise on those Facebook groups.