My grandmother is so crazy?

your grandma probably grew up in an abusive household.people sometimes only know what they are taught.it's hard to break ingrained patterns. if her behavior is worse than it used to be, it's possible she's suffering some sort of mental illness.rather than responding to her with anger, be nice whenever possible.she's probably so used to fighting with people that kindness might surprise her.and I would just ignore stuff she says about you. i'm sure your relatives are aware of how she exaggerates. and who cares about dumb stuff you did when you were a kid.just laugh it off and say,yeah I made some mistakes when I was a kid. and give your sister your time and affection so that the only adult in her life isn't this crazy grandma.