Kinda long so I'm sorry.

My sister is only 17 years old and has openly admitted to being jealous of my pregnancy. When me and my Fiance announced our pregnancy not even a week later she said she got a positive test which we all knew was lie (She said she threw it away and almost everyone keeps their first positive test) so my mom took her to an OB and they of course told her she wasn't, she literally broke down and was depressed for a couple days. Well today she goes on and on about how I have no morals for getting pregnant at 18 and having my daughter after I turn 19. She went on saying that everyone in my family including my Fiance spoils me. She doesn't understand that he's my Fiance so he's going to and that when my family buys stuff for the baby it's not for me like I'm not gonna be wearing diapers or newborn clothes. My child will be the first grandchild and first great-grandchild so yea they go a little overboard sometimes. She was diagnosed with PCOS and endometriosis and was told it'll be hard for her to conceive so I understand a little of her jealousy I guess. I have no idea how to make her realize that she needs to get over my pregnancy otherwise she's gonna suffer and that's it's gonna get worse once the baby is here. Anyone else experience this?