Exactly Kathy, well said once again.
Regarding the forgetfulness issue, that is not exclusive to Evie. The overwhelming anxiety that is thrust upon a sufferer often limits the brains ability to find information readily, hence another term being stressed. Those without PTSD can forget easily information when stressed, though when you expand this three fold or more due to the nature and size of stress from PTSD, finding information within the brain can be a daunting task.
This is why when anxiety prevails a sufferer must retreat if overwhelmed, they must use relaxation first and foremost, or something that they can do to relax. This immediately relieves the stress upon the brain, which allows them access to the information more readily. The problem here is often pride, in that we may do bad things, say bad things due to a lack of ability to access the information within our brain, however; we then build another realm of problems from guilt. These are all learning issues and one's in which must be learnt individually.
What you do is correct, in that you prompt Evie to the point of what occurred at which point she can then choose to acknowledge what is going on and then discuss the problems and feelings associated. Your method is what all carers should use compared to other more aggressive manners. Firm but fair is needed to deal with a sufferer though more importantly, to get the sufferer dealing with themselves at times.
Travis will learn.... just as we all do dealing with PTSD.
Well done though Travis just for being with Evie during her ordeal.... just being their is the right thing to do.