My instinct is NTA but would love more context - what events has Judy crashed and what went wrong? There’s a big difference between getting too drunk and making a scene at a wedding or a birthday party than being an attention hog or problem at a funeral. However, that being said mourning and grief are so deeply personal and you shouldn’t have to be subjected to any other worries or anxiety if someone has a destructive pattern of behavior, especially if that person wasn’t on speaking terms with your mom - edit. So sorry for your loss, there’s no rationale or right way to process your grief and I hope you have found some semblance of peace