Advice: Sibling Sensitivities

I'm pregnant with my first child and very excited, especially about sharing the experience with family and friends. My older sister has six children—and a lot of wisdom I'm open to hearing. Unfortunately, she seems offended by the fact that I'm also reading books and researching things on my own—she says I'm demonstrating that I don't care about what she has to say and I'm trying to make her look stupid. My sister apparently thinks that she knows better than the entire medical and scientific community. Unless I take her advice without question and without referencing other sources, she refuses to talk to me. How do I get through to her?