That npr article had a poignant quote explaining why having a separate entrance or at least a solid wall (preferably sound-proof) between you and the extended family is the sine qua non of multi-generational living.
Separate 2nd unit living: good for family. good for keeping your sanity."Our nerves are shot because we siblings, we love our family but we don't like living with them," Suckow says. "It's like one big holiday dinner that won't end. You can't gohome after the turkey is carved."