My sister is 46 years old, has a teenage son, and my parents are still supporting her. They're paying her mortgage. She was a drug addict and alcoholic for about 25 years, has only been clean for about 7 or 8 (as far as I know) and is a master manipulator. She's an impulsive, hysterical bully. She often gets her way just by running over everything, and everyone, in her path.
She has a sense of entitlement that is absolutely breathtaking. She always has a new car, designer everything, she buys her son iPads, laptops, cell phones, and then, for some reason beyond her grasp, has no money to pay her bills. So my parents do it---even though they are in their 80s and my dad is suffering from advanced heart disease, cancer and Alzheimers.
And what does loser-sister do for a living? She's a loan officer at a bank. (insert obvious joke of your choice here)
If it weren't for my nephew, I would never EVER speak to her again. The OP can at least say that he still loves his brother. I can't honestly say that about my sister. I really can't.