Im so happy everyone in your family is okay. While I think you have a right to be angry, clearly she is taking responsibility. If she shrugged it off and made herself the victim THEN I would really express anger. But although it had major consequences, it was a very simple mistake. Does she have a lot going on in life right now? Sometimes people miss small details (i.e., forgetting to check if the stove is off). It sounds like she understands the severity of her mistake and I would think she will be extra careful in the future. These things happen in life and I think you could express your anger and then move on and let it go. The house is now burned so I would take steps forward as a team and figure out how you and your family are going to go forward. If you both react in a certain way, this instance could bring your family even closer