This woman will never change her ways. Jailing her would at least reduce the risk of her injuring or killing someone else on her self-destructive odyssey.
Not sending her to jail implicitly condones her behaviour, much as haphash
has done on this thread, and encourages her to think that she doesn't need to change her ways as "it will all be okay" at court.
You can't forcibly 'cure' an addict, but by detaining them you may encourage them to think seriously about 'curing' themselves, and the potential consequences if they don't. As long as it isn't a problem for Lindsay (hey, what's a couple of hours in court every few months!) she'll never think about modifying her lifestyle and behaviour.
It is often said that an addict must hit bottom before they will commit to recovery, the court system et al keep catching Lindsay before she gets there and propping her up, and I don't believe it is doing her any favours in the long term.
Frankly at this point I suspect only a hospital scare following an overdose of partying will shake her from her unwavering conviction that she can do what she wants with impunity. Sadly i think someone is going to have to die, or nearly die to get through to her.
If there is any justice, it will only be Lindsay, and not some bystander she hits with her car while wasted one night.