I'm not going to give my sister money
Why wouldn't you give her money?
It's my money and I'm tired of her begging all the time.
Well, you did earn that money and it is your right to do with it as you wish.  I hope she can find a different way of solving her financial issues!
She's a leech.
It sounds like she's depending on you for help instead of trying to find her own way. Maybe you could assist her in her jobsearch.