I'm not sure I perceive it in that way.
I think she's just lost a number of relatives in a horrific incident and she's trying to join the dots up of something that doesn't make sense to her.
Imo we have to remember that although AE may not have been very close to her Uncle and Aunt or have known Sheila and Jeremy very well however they were always there in the background as part of her extended family. June was her Mother's sister so they were part of her history and security.
Innocents, including myself when I was, rightly argue that JB was bound to be traumatised and shocked by the murders if he was innocent because he had lost everybody and then tend to forget the absolute horror for Ann as a young woman also the rest of the family. Pamela, her mum must have been totally distraught so it's no wonder Ann was angry and determined to find the perpetrator. ...... in other words we need to remember she would have been traumatised as well and therefore may have behaved in ways considered over the top, difficult to understand etc.
