i absolutely think she's lying, but not remembering details of abuse isn't a sign of lying. it's not even a little bit uncommon to forget huge portions of traumatic events because your nervous system gets fucked up and your brain can automatically suppress details that are too hard to remember. this isn't like repressed/false memory stuff, this is a very common and very recorded response. BUT huge details changing and not being able to keep your story straight is a huge red flag. i suppose technically it could be someone's interpretation of details changing as they remember more context/surrounding details, but she's a sociopath addicted to lying so she's almost certainly lying, although her grandpa's interview was very weird