Deadbeat brother sends daughter to me w/ her car problems
	
	
		My older brother is nearly 50 and an alcoholic. As such, his income isn't terrific, but he makes enough to pay rent and afford his bar tabs.  I own a livery company and do pretty well, but I work very hard to keep things running.  For about the past 5 years, my brother has been sending his 22 year-old daughter over to my company mechanic whenever her car breaks down.  He never asks me, just tells his daughter "your uncle's mechanic will fix your car." and she shows up.  This puts my mechanic in the awkward position of having to call me to okay the work and me in the awkward position of having to pretend I knew she was coming.  My niece is a single mother and works minimum wage jobs to make ends meet. 
  I love my niece very much but my brother is making me crazy.   What's more, I've happily fixed my neice's car several times over but my mechanic has a whole fleet of vehicles he has to keep running, and I just can't keep doing this anymore. Like I said, my brother never asks me and never offers a dime.  
  How do I put a stop to this without looking like the bad guy in my neice's eyes?