Yes, definitely try milk thistle - although if you can get her to take pills, that's probably best. According to the University of Maryland summary, tinctures (alcohol extracts) of milk thistle may be less effective and they recommend avoiding them. Also, when the ingredients are the same, I usually prefer supplements and medications manufactured for human consumption, since they have stricter controls on potency and purity.

The UMd site doesn't have a specific discussion of toxic liver damage, but their articles on cirrhosis and viral hepatitis have some more information that might be helpful to Sara.