My husbands sister gets in the way of our marriage what can I do?

Elaborate please.

Yes in what ways, does sister live with you and husband

Shoe attitude to your husband... nor remind him even your a humanbeing and show feelings to you

Tell your husband, that you know they are family, and that they love each other. But You are his wife now, and you deserve every love and respect from him as any normal wife deserves from her husband.
That's all I can say for now, due to the lack of information you gave us. Sorry.

I guess it depends weather it has something to do wit the culture... I have some experience with that... maybe showing some respect so he can see that you r interested in their relationship but showing him that you come before anyone since you are eventually going to be or is the mother of his kids... dont rush give it some time!!

Show him what he would be missing if she did ruin it