Thanks, but if you read it carefully it does necessarily suggest she was drunk driving at all. It actually fits in very well with the fact that we know, she pulls her car off into the woods to drink and sleep it off. It didn’t say when she had pulled the car off the road into the woods. It would be a bit coincidental if she was just driving along drunk and decided she wanted to ring Harrison and by pure chance pulled over into the woods to ring him, in the very place she normally drives to before drinking.
If you look at the start of that synopsis she was supposed to be going out for a couple of hours to meet some people but Susan gave her the very opportunity of doing what she did, by getting Chris and Martha to stay with her for the night so Alice could get some rest. And why is she afraid to go home if there is no one there. Because she does not want to drive whilst drunk?
Even in the much more unlikely scenario that she was drunk driving against her normal pattern, that could have been the incident that made her realise how dangerous it was. However it would seem very unlikely given she pulls over in the woods to drink and sleep it off.
After not being able to plead guilty on Friday, she said about driving drunk and bridgegate she wouldn’t and couldn’t . Which is different from never have. Though that synopsis does not prove she ever has.
After bridgegate and horrified at her supposed behaviour of driving and causing it, she makes the wrenching decision to give Martha up to Chris. He reassured her that he knew she would never put Martha in danger,. She was so disgusted at herself at what (supposedly) had happened, she pointed out that it could not be guaranteed.
Her willingness to take responsibility for something she hadn’t actually done, and despite feeling she could not have done, is why I believe the key in the glovebox has (as is clearly repeatedly implied) always worked for her since she started doing it, as otherwise she would have known and admitted to it.
Of course far from ideal and danger of driving with residual alcohol in system the following morning. I assume she used the car in the woods, so she can be totally alone without fear of anyone turning up - until George.