Unwanted advice rant/vent

This is my first pregnancy and now everyone is an expert. I appreciate the advice and help to an extent but some of the things I don't want to hear just yet! How do I deal with this politely? My SIL is the worst. She has no tact about her and is fine showing her stretch marks at a dinner party and telling me ACROSS my crowded house that benefiber was going to be my best friend. When she asked if she was saying too much I said "I just don't want to hear anything scary" tying to shut her up and give her a hint while keeping it light. She responds "oh it's not scary! The only scary thing is _____" and proceeds to tell me a few different terrifying stories! More than once. Yall. What do I do here? She's going to drive me insane.