Unreliable in-laws

We have a 2 year old. We asked my sister in law months ago to take my son when I go into labor and she said of course. She lives 25 minutes away. Suddenly my mother in law is saying that she’s coming to stay at our house when I go into labor. Problem is she lives 2.5 hours away with no traffic. My SIL is in her 40’s with a teen and 8 year old so I don’t see why she can’t take my son. Shes also a SAHM so no job to worry about. She’s saying she’s not sure if she’ll be able to. It’s so upsetting to me that my husbands own sister isn’t willing to help us out. My family is also 2 hour drive plus they all work but I know if they lived closer, they would 100% help us out.

My family is the kind to go out of their way to provide help and support. My husbands family doesn’t lift a finger unless it somehow benefits them too. It’s so frustrating. At this point, if my water breaks at night the way it did with my son, my husband is not going to be there for labor and delivery and I will be by myself.