Parent problems urgent help please?

I have a gorgeous, beautiful house which I love dearly. I know its stupid but this house means alot to me because i grew up here and because its nothing like any other house. Now.. My mum is a party animal, a spendaholic and uses my centrelink youth allowance to pay off her credit card bills and debt. She also wants to knock down the house which would also involve getting rid of the trees, cubby house and pool on our large land so she can re-build 3 ugly 'modern' duplexes on it so she can sell them to other people - therefore sharing the land with strangers. What can I do to prevent this? Im getting a job at the bank soon..maybe I could pay off her debt just so I can keep the house the way it is. Help - Im getting depressed and im sick of her menopause and stupid ideas. Its bad to say this but I wish she would move countries and leave just so she doesnt sell anymore things of mine and my dads just for her pleasure.. =(