I really think my mother in law is starting to become obsessive!?

she constantly calls daily! asks about me and the baby she tells all her dreams about having a big house with a room for mackenzie and about winning the lottery to buy her everything she wants and every time i talk to her she tells me how much she loves her and always talks about how is going to watch her she even has a crib set up for her with a playpen and bouncy seat she even comes into my house and rearranges the baby room and pulls open every drawer to look at her onsies? how she is going to take 2 weeks vacation when the baby is born and she constantly rubs and talks to my belly my husbands has even yelled at her to back off and i tell all the time if not going to be necessary because i will be working 2 days a week after she born! i feel like she tryng to to steal our child because she was never there for my husband i know her intentions are good but she is driving a fine line between psychotic and obsessive how can i get her to back off because us not telling her nicely or yelling it is working! Its getting to the point my husband and i are fighting about it because i just want peace! she never acted like this before our house burn't down a year ago and i shortly learned after i was pregnant we have a new house now even my FIL has told her to back off and she won't what do i do?