It's a lot more complicated
1) The Koran says nothing about punishment for drinking alcohol. While it's seen as something Not Good, the Muslim good book considers it to be more a personal matter between the sinner and God.
2) Sisters in Islam, a Malaysian women's Muslim group, has condemned the practice as "cruel and inhuman" and has urged the woman in question, several times, to appeal the decision. With the Koran on their side, there's a good chance the ruling may be mitigated, if not reversed. The woman doesn't want to.
3) The govt. (not the Islamic court) has also tried to give the woman an "out" by suggesting appeal avenues, jail terms (which will, in all probability, quietly melt away to a quick shoo out the door after a couple of months).
4) No man has been caned for alcohol consumption in the past few years; this woman is the first.
So, bearing all the above in mind, why is the woman wanting to go through with it? Only she knows.