My sister and I live at home, we are both full grown adults. My parents have a pet dog and she had a pet chinchilla. Last week, my brother came over to have a talk with us about a life-threatening health issue he was diagnosed with. But that's not the subject that's the issue. He brought his dog over to play with ours. Somehow one or both got into my sister's chinchilla cage and killed it. My parent's dog brought it to us and my sister freaked out. It took about an hour for her to stop screaming and accept that it was dead. It has now been over a week and she refuses to sleep in bedroom, she barely eats, speaks to anyone and mistreats the dog. We understand that it was shocking to her, but she's not being rational, throwing tantrums like she's a child and claiming the dog "knew" the chinchilla was a part of the family. Her behavior is affecting my parents and I can't take it. She doesn't even seem to care that our brother is sick, it's like the chinchilla's passing overshadows even a human life. If we talk to her about her behavior, eating or sleeping in her room, she just snaps back and says we don't understand. She's not the only person something like this has happened to, and there are far worse things going on in our family, and she has experienced worse things in her life. The worst part is blaming an animal, the dogs don't know any better, they didn't "murder" the chinchilla, it was an unfortunate accident, dogs are the natural predators of rodents after all, they can't be expected to control their instincts if she never bothered to get them used to the chinchilla. I just don't know how to get her to see that she's not dealing with this in a healthy way.
My guess is that she's actually not freaking out about the Chinchilla, but rather it is either the issue with your brother, or some past trauma that was re-triggered by this shocking event, or some combination of the above. As you say, her reaction is way out of proportion, and pretty irrational. But you say she's been through a lot in her past. Sometimes a rather small, but upsetting event can be the thing that tips the balance and ignites a lot of repressed emotions that were hidden.
This is just the sort of situation that would most likely be quickly alleviated with Meridian Tapping/EFT, if she would be willing to give it a try.
Using tapping, she could start with the trauma and shock of seeing her pet killed by the dog. This would very likely reduce her anger and grief immediately, and I'd be willing to bet that another wave of new emotion would come in to take it's place -- having to do with some past event, or maybe grief and fear about your brother's illness. Then this too could be alleviated with further tapping to address whatever those issues are.
The only other possibility I can think of, although less likely, is that she's experiencing some kind of psychotic or manic episode (if her behavior seems extremely unusual, delusional, paranoid, or if she's hallucinating... not sleeping at all, etc). But if she has no prior history of mental illness, then this is probably not the case.
If nothing else works and she remains in this state, it would be a good idea to try to get her to go with you to see a therapist.
Ben Schwarcz, MFT
Santa Rosa Psychotherapist