I need some advice , before I get into this

Brittany • Christian Mother , & wife ,baby number two Due march 27th??
Hey ladies , right now when I think about the situation my blood boils . So I need to see it from a Different Stand point . Me and DH are in the process of building our first home together on our land . The land used to be my husbands great grandmothers , but he inherited it . She is still alive but the home that she is living in is literally falling down around her . Which is not a safe environment for a disabled elderly woman . My mother in law who I love  with my everything is living in a camper on the land to help take care of her . I do not want to talk negative about my Mother in law she's been like a mother to me . However she is the type of woman who likes to take control over things she's very nurturing and motherly .when our home is finished she will still come to help with her grandmother which I greatly appreciate . I have a one year old who needs my attention . I'm just worried that she's going to move in on top of us and try and take over . I'm a stay at home mom and wife , I don't want her to help me with anything around the house other then with her grandmother . Such as cleaning , cooking ect .. I feel like those are my jobs as a wife and mother . I don't want her to make me feel like less of a mom / wife . Because she insist on "helping" with things I do not need help with . I do not know how to address this matter with her , I'm sure she understands that I want family time but when were in the situation I feel like it'll be a different story . I don't want to feel suffocated with her being there . How should I approach this ?