Thoughts on renting from family?

Ka

So where we live right now we pay $800 in rent a month, plus $400 a month in electric. The managers here are awful. Ive contacted them multiple times about black mold growing in the bathrooms, a leaky roof, blinds that are broken, our heater not working and the maintenance man came over and he said all these issues are our fault, which their not and i have documentation that some of these issues were here before. Anyways I was talking to my grandmother and she offered to rent us her upstairs apartment which is a 3 bedroom 2 bath place for $500 a month. This would help us out financially so much since we are trying to get back on our feet after unexpected lay offs and medical problems. We have twins and one on the way. I told my parents who live only 2 streets over and they basically said its a terrible idea and that they would be hurt if we move away (only 20 mins away) and I'm so stuck and upset on what to do...

Does anyone have any experience renting from family and it went okay? Anyone have bad experiences? Let me hear all of them. Thank you in advance!