Family drama

Has anyone had any family say negative things (plain out lies) about your pregnancy ? 
I have a step sister who has jealousy issues (she's 21) im 27 ... We've never been close but I've always been polite. When she found out I was pregnant I never got so much as a congratulatory text. That's ok I didn't expect one. 
My first cousins who are like sisters tell me she's basically been saying I tricked my husband into getting me pregnant. And she hopes he can handle it. 
Mind you we've been married 6 years im a teacher and having a baby in May do you think that's a coincidence? Nope .... I'm am done how do I cut her out of my life completely ?