Owed money by piss taking sister. what can i do?

i lent my sister alot of money a couple of years back as she was pregnant and told me she was going to lose her house and husband due to her debts. me being soft as i am i fell for her sob story and gave her the money with the promise that she'd pay it back when she could. however 2 years on and i not got a penny back, she says she is skint and she is having to spend all she earns on stuff for kiddie and mortgage payments ect.... however, in last month she has brought a �1000 tv, playstation 3, a treadmill and a �600 carpet. she claims she has thousands in bank to do garden up and the cheeky ***** rings me and tells me about it all!!!!!!!! i am like HELLO SHOULDN'T YOU BE PAYING ME OFF FIRST?!?! what can i do? i realise she is family and i not wanna cause a mive ruckus, as no doubt parents would get involved, but i am far from rich and need the money - obviously more than she does. i do not buy any such luxury items for myself, so why the hell should she? any advice people? thanks