Legalities of insanity....

Okay so my mother is becoming crazy, if not already completely off the deep end.

recap on the whys....
~She was allegedly raped by her father and her local priest allegedly took pornographic photos as well as molested her (i only say 'allegedly' because with him dead this cannot go through court nor was i there to confirm this but i do believe this happened, its too consistent to be a lie, she always adds details to her lies the more she tells them). As such when she told her family about this as adults they kinda abandoned her...
~She had an 'accident' back when i was 8; this other woman (lets call her J) had a fight with her husband, their daughter (S) came to our house, on a property btw, to get away, without really telling us why she was there. Next morning most of us have gone to school, S included. J comes to our place in her four wheel drive car (this will be sorta important) mum goes out to find out whats going on, mum finds out why S came over night before, tries to tell J not to worry.... J rolls her car onto my mums bare foot, spins the wheel, reverses so she can then run over my mum who has since fainted..... only not doing so since my father came rushing out of the house like a raging bull (my elder sister who had graduated by then's recount of the incident)... saw a therapist for a bit who started helping her, only to have her stop going
~For years she had this habit of fabricating or exaggerating something with me to the point that I thought i was the crazy one; prime example of when i was 15 having a lord of the rings marathon hadn't moved or spoken since fellowship and was half way through return of the king, about 3.00pm, when she comes screaming in from outside yelling at me for calling her names and telling her to feed the horse herself coz i wasn't going to do it.... i don't feed the horses until 4.30 and i know i didn't tell her any of that...
~it used to be when my father and her fought i caught the shit, basically the scapegoat for all his 'crimes' against her at that time. if he called her i bitch, it meant i did too... if he took something i was in on it..... if he was turning everyone against her i was helping. i tried telling my older sisters about it, who were out of the house by then, and they never believed me, told me to just put my head down and stop antagonising if i didn't want to be yelled at... which totally works....
(direct quote from her btw; "I always wanted more children, but i never wanted YOU.")
~Dad died suddenly on Halloween 6 years ago, wasn't meant to die supposed to be fine but our local hospital fucked up extremely.

Fast forward to now;
~Our relationship is kinda good, she realises a lot of what she did made me who i was, wont admit to any of it but 'i cant help the way you feel'
-she's suddenly gone extreme, yelling at my sisters over little to nothing, believing they hate her, they lied to her, they're gunna keep her grandchildren away from her etc. basically all the shit i used to cop over years suddenly dumped on the angel children with no warning.... wont lie its satisfying for them to finally realise that i wasn't the one lying
~always, and i do mean always like just about every conversation, brings up her molestation and/or ptsd... even to strangers. but and i quote "i cant go to a therapist because the one who knows everything doesn't have time for me and i cant talk about it to someone else because it hurts and i breakdown and I'm doing fine really its just this time of year" word for word what she said to me.....

My question, is there a legal way I can force this woman to go to therapy, that even her doctor is encouraging, without facing the backlash because I'm living with her until I can get a house? do you know how tempting it is, when she's driving everyone away with this craziness, to tie her up and throw her into a mental institution? (does Australia even have any?)