Creators syndicate which distributes her column has a bio and a page with a recent column and links at the bottom to a few previous columns.
You can also find an archive going back to early 2000 of her column in Working Asset's Workingforchagne.com. They have a newsletter which will alert you when new columns go online.
There is a page with her pieces for the Texas Observer (and mollyivins.com takes you to their front page with a plea from her to donate to the magazine).
You can find her pieces in the Progressive by doing a search on their site.
Bushflash interviewed Ivins on July 10, 2003.