I don't mean to sound rude or lack empathy, but seriously what is wrong with you??
I don't care what is wrong with her. You shouldn't care what is wrong with her. She has shown who she is, that is all we need to know.
We can not diagnose people with true diagnosis, we can not fix people, unless we have a doctorate in that degree, and that said person wants help.
We CAN fix ourselves. We CAN become stronger and healthier.
You could spend years trying to diagnose her, or try to figure out what you think it is, or try to find a way to enable her, by saying "Well, she has other issues, thats why she does it".....come on. Seriously Stop.
If you must have a reason for why she tried to jump out of the car, while not being intoxicated, here it is. Plain and Simple.
An alcoholic in recovery sometimes doesn't reach full brain capacity (brain fog lifted) for up to 18 months after gaining sobriety. Just because a person is not actively drinking at the moment, or today, doesn't mean they aren't under the influence. That would be my bet. A person who quits drinking without going through the steps or some sort of rehab, is simply not an active alcoholic. There is a difference between a recovering alcoholic and one that is simply not drinking for awhile.
One that is not drinking, still has alcoholic thoughts. They usually, not always, but often will hold resentments for the reason why they are not drinking. It may be against the person that told them to quit drinking or they were leaving. It could be against themselves for not understanding why they can't just have a drink and walk away. Whatever the reason they hold resentments, they usually will end up drinking again, because they as a PERSON have not healed mind, body and soul.
Alright, probably more deeper than what you asked for, but there is millions of people in this world. You can't save any single one of them from themselves but you certainly can find 1 out of the millions that is not caught up in this lovely disease.