There are several options that might interest her. Can you be a bit more specific about the problem(s)?
In the meantime, here are a few compounds you might look into:
GABA (amino acid, good for anxiety, increases alpha brain wave production - great for relaxation)
Kava kava (herb, helps some people with anxiety-type symptoms - I've heard tinctures work best)
L-Theanine (amino acid, has a calming effect, possibly a slight mood lift)
5-HTP (amino acid, used as a mood enhancer, has a relaxing effect on some people)
If you're looking for a good herbal blend for general stress then I highly recommend "Stress Advantage" by New Chapter (it combines a select group of adaptogenic herbs). I would also suggest a good multi to make sure she's not deficient in something.
Cheers! (literally)