Feeling left out

My oldest older SIL, Amanda has a son, he'll be one this November. When she got pregnant everyone was so excited and happy for her. Now my boyfriend and I are expecting and there's not much excitement. My younger older SIL, Sam told Amanda that it'll be different because I'm not her sister so there's no reason to try and be close with our new family. I may not be her sister but her brother is the father for crying out loud. I just felt so disrespected that she feels it'll be different and our child is less than Amanda's. Just seems like all the baby hype was given to Amanda with Benny and now myself and my boyfriend feel like people aren't excited at all. Just ranting. Upset. Hormonal.