Why does my mom treat my Aunt so much better than me.?

I'm adopted and I have always felt like my mom loved her family (her brother, and sister) more than me. She is the olderest, she always talks about how bad they treat her and yet she jumps through her butt for them. My mom is diasbled due to a really bad wreak. She was watching my Aunt's ( the youngest) sonfo� her and when my aunt Lost herjobmymom watched him for free. That would of been all well and fine but at that time my aunt was still finding money to buy expensive things. This was all while we could barley pay our rent. My mom is owed to this day about $5,000 in baby sitting money and we lost our house as we'll... Also there was an issue about my name still legally being my birth name. My parents waited till I was 15 to tell me. I was really embarassed by that, and hurt. My mom told my Aunt and I wished she wouldn't well my Aunt told the rest of the family. She also told them that I slept with a bunch of guys. I confronted my Aunt and to this day I don't think my mom has ever said anything about it. Well today I find out that my mom is giving my Aunt a $250 dog. She's gonna have me pay full price. What makes me made is my parents can't even put gas in their car because they are so broke and I'm having to help them. I don't mind helping but this whole thing seems messed up. My Aunt is a ***** and I'm so tired of coming in second to my damn aunt. Talking to her doesn't do any good I gave up on that but how do I deal with this?!? ( Sorry for typos I'm writing this one my phone)