If she lived in a bad neighborhood? And by "bad," I mean drug deals happening around the corner, multiple calls to 911 for this neighborhood (fights, gun shots, etc).
If your mom or MIL lived in this neighborhood, would your kids be able to spend the night there, hang out there all day or would you prefer grandma come to your house to visit?
This is my mom. I got to thinking about posting this after she told me what happened Friday morning, with some fool just randomly shooting, putting bullets into my aunt's apartment, who also lives there. And it's not like she never sees the kids. Every weekend, the girls call her to see if she wants to go to the park or wherever, even if it's just my errands to the stores.
I've seen a couple of replies about financially helping her move somewhere better. Believe me, if I could I would. But, I can't make that happen. I've recently been diagnosed with leukemia and my meds cost me (after insurance pays) $1500 a month and we are currently struggling until things get worked out.