I think my parents tried to treat us equally. I felt like my mom especially was equal, but I did perceive her as more attached to my younger sister, but as an adult I think that was a function of my sister being younger more than anything. The baby needed more help, and even I thought she was cute like a doll and used to throw her around and make her giggle.
My dad was more worried about my sister for various reasons and that came across to her as him not loving her as much, and she still feels like I was the golden child and she was the one picked up on. Unfortunately, some people have reinforced this idea by affirming there is “always one” that is abused. As I said above, she was the youngest, so it is no surprise she was more bonded with my mom when we were very young and I was with my dad, I think that happens a lot because of birth order.
Drives me crazy. She is sure she gets less money from them, total bullshit, and that my dad doesn’t like her, also total bullshit. When I say money I mean for weddings, birthdays, gifts. Neither us are supported by my parents in any way.